MARTIN MIDSTREAM PARTNERS L.P., 10-K filed on 2/23/2026
Annual Report
v3.25.4
Cover Page - USD ($)
 12 Months Ended
Dec. 31, 2025
Feb. 23, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 000-50056    
Entity Registrant Name MARTIN MIDSTREAM PARTNERS L.P.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 05-0527861    
Entity Address, Address Line One 4200 Stone Road    
Entity Address, City or Town Kilgore    
Entity Address, State or Province TX    
Entity Address, Postal Zip Code 75662    
City Area Code 903    
Local Phone Number 983-6200    
Title of each class Common Units representing limited partnership interests    
Trading Symbol(s) MMLP    
Name of each exchange on which registered NASDAQ    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction false    
Entity Shell Company false    
Entity Public Float     $ 78,689,869
Entity Common Stock, Shares Outstanding (in shares)   39,055,086  
Documents Incorporated by Reference None.    
Entity Central Index Key 0001176334    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Amendment Flag false    
v3.25.4
Audit Information
 12 Months Ended
Dec. 31, 2025
Audit Information [Abstract]  
Auditor Name KPMG LLP
Auditor Firm ID 185
Auditor Location Dallas, Texas
v3.25.4
CONSOLIDATED BALANCE SHEETS - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Assets    
Cash $ 49 $ 55
Trade and accrued accounts receivable, less allowance for doubtful accounts of $310 and $940, respectively 58,371 53,569
Inventories 50,248 51,707
Due from affiliates 8,942 13,694
Other current assets 12,298 11,454
Total current assets 129,908 130,479
Property, plant and equipment, at cost 970,753 954,059
Accumulated depreciation (681,527) (648,609)
Property, plant and equipment, net 289,226 305,450
Goodwill 16,671 16,671
Right-of-use assets 69,938 67,140
Investment in DSM Semichem LLC 6,198 7,314
Deferred income taxes, net 9,026 9,946
Intangibles and other assets, net 1,451 1,509
Total assets 522,418 538,509
Liabilities and Partners’ Capital (Deficit)    
Current portion of long term debt and finance lease obligations 15 14
Trade and other accounts payable 57,814 61,599
Product exchange payables 169 798
Due to affiliates 13,286 4,927
Income taxes payable 1,580 1,283
Other accrued liabilities 51,279 46,880
Total current liabilities 124,143 115,501
Long-term debt, net 428,008 437,635
Finance lease obligations 39 55
Operating lease liabilities 48,353 47,815
Other long-term obligations 7,670 7,942
Total liabilities 608,213 608,948
Commitments and contingencies
Partners’ capital (deficit) (85,795) (70,439)
Total partners’ capital (deficit) (85,795) (70,439)
Total liabilities and partners' capital $ 522,418 $ 538,509
Other Receivable, after Allowance for Credit Loss, Current, Related Party [Extensible Enumeration] Affiliated Entity [Member] Affiliated Entity [Member]
Other Liability, Current, Related Party [Extensible Enumeration] Affiliated Entity [Member] Affiliated Entity [Member]
v3.25.4
CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Statement of Financial Position [Abstract]    
Allowance for doubtful accounts $ 310 $ 940
v3.25.4
CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Revenues:      
Revenues $ 716,113 $ 707,622 $ 797,963
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold 318,623 297,036 389,680
Expenses:      
Operating expenses [1] 258,431 255,586 252,211
Selling, general and administrative [1] 42,004 48,502 40,826
Depreciation and amortization 50,197 50,787 49,895
Total costs and expenses 669,255 651,911 732,612
Other operating income (loss), net 2,039 1,584 1,373
Operating income 48,897 57,295 66,724
Other income (expense):      
Interest expense, net (57,787) (57,706) (60,290)
Equity in loss of DSM Semichem LLC (1,116) (624) 0
Loss on extinguishment of debt 0 0 (5,121)
Other, net 33 25 56
Total other income (expense) (58,870) (58,305) (65,355)
Net income (loss) before taxes (9,973) (1,010) 1,369
Income tax expense (4,772) (4,197) (5,918)
Net loss (14,745) (5,207) (4,549)
Less general partner's interest in net loss 295 104 91
Less loss allocable to unvested restricted units 61 25 14
Limited partners' interest in net loss $ (14,389) $ (5,078) $ (4,444)
Net loss per unit attributable to limited partners - basic (in dollars per share) $ (0.37) $ (0.13) $ (0.11)
Net loss per unit attributable to limited partners - diluted (in dollars per share) $ (0.37) $ (0.13) $ (0.11)
Weighted average limited partner units - basic (in shares) 38,890,039 38,831,355 38,771,657
Weighted average limited partner units - diluted (in shares) 38,890,039 38,831,355 38,771,657
Terminalling and storage      
Revenues:      
Revenues [1] $ 90,831 $ 89,067 $ 86,514
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold [1] 0 72 75
Transportation      
Revenues:      
Revenues [1] 212,509 223,934 223,677
Sulfur services      
Revenues:      
Revenues 16,441 14,572 13,430
Product sales      
Revenues:      
Revenues [1] 396,332 380,049 474,342
Specialty products      
Revenues:      
Revenues [1] 248,694 264,850 346,777
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold [1] 217,157 228,600 305,903
Sulfur services      
Revenues:      
Revenues [1] 147,638 115,199 127,565
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold [1] $ 101,466 $ 68,364 $ 83,702
[1] Related Party Transactions Included Above
Year Ended December 31,
 202520242023
Revenues:   
Terminalling and storage$72,244 $71,799 $72,138 
Transportation30,428 33,250 29,276 
Sulfur Services— 664 — 
Product sales4,243 457 8,767 
Costs and expenses:   
Cost of products sold: (excluding depreciation and amortization)   
Specialty products28,626 31,789 35,930 
Sulfur services12,885 11,915 11,182 
          Terminalling and storage— 72 75 
Expenses:   
Operating expenses111,169 106,831 100,851 
Selling, general and administrative31,698 39,385 32,021 
v3.25.4
CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Revenues:      
Revenues $ 716,113 $ 707,622 $ 797,963
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold 318,623 297,036 389,680
Expenses:      
Operating expenses [1] 258,431 255,586 252,211
Selling, general and administrative [1] 42,004 48,502 40,826
Terminalling and storage      
Revenues:      
Revenues [1] 90,831 89,067 86,514
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold [1] 0 72 75
Transportation      
Revenues:      
Revenues [1] 212,509 223,934 223,677
Product sales      
Revenues:      
Revenues [1] 396,332 380,049 474,342
Specialty products      
Revenues:      
Revenues [1] 248,694 264,850 346,777
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold [1] 217,157 228,600 305,903
Sulfur services      
Revenues:      
Revenues [1] 147,638 115,199 127,565
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold [1] 101,466 68,364 83,702
Related Party      
Revenues:      
Revenues 106,915 106,170 110,181
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold 41,511 43,776 47,187
Expenses:      
Operating expenses 111,169 106,831 100,851
Selling, general and administrative 31,698 39,385 32,021
Related Party | Terminalling and storage      
Revenues:      
Revenues 72,244 71,799 72,138
Related Party | Transportation      
Revenues:      
Revenues 30,428 33,250 29,276
Expenses:      
Operating expenses 81,835 79,441 73,866
Selling, general and administrative 8,533 11,218 8,927
Related Party | Sulfur Services      
Revenues:      
Revenues 0 664 0
Related Party | Product sales      
Revenues:      
Revenues 4,243 457 8,767
Related Party | Specialty products      
Revenues:      
Revenues 578 352 8,547
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold 28,626 31,789 35,930
Expenses:      
Selling, general and administrative 4,240 5,454 4,152
Related Party | Sulfur services      
Revenues:      
Revenues 3,665 105 220
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold 12,885 11,915 11,182
Expenses:      
Operating expenses 5,609 4,888 5,738
Selling, general and administrative 3,800 5,427 3,714
Related Party | Terminalling and storage      
Cost of products sold: (excluding depreciation and amortization)      
Cost of products sold 0 72 75
Expenses:      
Operating expenses 23,725 22,502 21,247
Selling, general and administrative $ 1,100 $ 3,051 $ 780
[1] Related Party Transactions Included Above
Year Ended December 31,
 202520242023
Revenues:   
Terminalling and storage$72,244 $71,799 $72,138 
Transportation30,428 33,250 29,276 
Sulfur Services— 664 — 
Product sales4,243 457 8,767 
Costs and expenses:   
Cost of products sold: (excluding depreciation and amortization)   
Specialty products28,626 31,789 35,930 
Sulfur services12,885 11,915 11,182 
          Terminalling and storage— 72 75 
Expenses:   
Operating expenses111,169 106,831 100,851 
Selling, general and administrative31,698 39,385 32,021 
v3.25.4
CONSOLIDATED STATEMENTS OF CHANGES IN CAPITAL (DEFICIT) - USD ($)
$ in Thousands
Total
Common
Common
General Partner Amount
Time Based Restricted Units
Common
Common
Beginning balance at Dec. 31, 2022 $ (59,445) $ (61,110) $ 1,665  
Beginning balance (in shares) at Dec. 31, 2022   38,850,750    
Increase (Decrease) in Partners' Capital        
Net loss (4,549) $ (4,458) (91)  
Issuance of time-based restricted units (in shares)       64,056
Cash distributions (793) (777) (16)  
Unit-based compensation 163 163    
Ending balance at Dec. 31, 2023 (64,624) $ (66,182) 1,558  
Ending balance (in shares) at Dec. 31, 2023   38,914,806    
Increase (Decrease) in Partners' Capital        
Net loss (5,207) $ (5,103) (104)  
Issuance of time-based restricted units (in shares)       86,280
Cash distributions (795) (779) (16)  
Unit-based compensation 187 187    
Ending balance at Dec. 31, 2024 (70,439) $ (71,877) 1,438  
Ending balance (in shares) at Dec. 31, 2024   39,001,086    
Increase (Decrease) in Partners' Capital        
Net loss (14,745) $ (14,450) (295)  
Issuance of time-based restricted units (in shares)       54,000
Cash distributions (797) (781) (16)  
Unit-based compensation 186 186    
Ending balance at Dec. 31, 2025 $ (85,795) $ (86,922) $ 1,127  
Ending balance (in shares) at Dec. 31, 2025   39,055,086    
v3.25.4
CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Cash flows from operating activities:      
Net loss $ (14,745) $ (5,207) $ (4,549)
Adjustments to reconcile net loss to net cash provided by operating activities:      
Depreciation and amortization 50,197 50,787 49,895
Amortization and write-off of deferred debt issue costs 3,280 3,085 3,978
Amortization of discount on notes payable 2,400 2,400 2,200
Deferred income tax expense 920 254 4,186
Gain on disposition or sale of property, plant, and equipment (2,039) (1,584) (1,373)
Loss on extinguishment of debt 0 0 5,121
Equity in loss of DSM Semichem LLC 1,116 624 0
Unit-based compensation 186 187 163
Change in current assets and liabilities, excluding effects of acquisitions and dispositions:      
Accounts and other receivables (4,802) (276) 26,348
Inventories 1,459 (8,079) 65,976
Due from affiliates 4,752 (5,770) 86
Other current assets (2,880) 88 4,739
Trade and other accounts payable (3,270) 10,228 (17,539)
Product exchange payables (629) 372 394
Due to affiliates 8,359 (1,407) (2,613)
Income taxes payable 297 631 (13)
Other accrued liabilities 1,663 600 2,880
Change in other non-current assets and liabilities (138) 1,418 (2,411)
Net cash provided by operating activities 46,126 48,351 137,468
Cash flows from investing activities:      
Payments for property, plant, and equipment (24,768) (42,008) (34,317)
Payments for plant turnaround costs (7,368) (10,897) (4,825)
Investment in DSM Semichem LLC 0 (6,938) 0
Proceeds from sale of property, plant, and equipment 2,123 1,242 5,482
Net cash used in investing activities (30,013) (58,601) (33,660)
Cash flows from financing activities:      
Payments of long-term debt (235,500) (244,500) (632,197)
Payments under finance lease obligations (14) (9) (9)
Proceeds from long-term debt 221,000 255,578 543,489
Payments of debt issuance costs (808) (23) (14,289)
Cash distributions paid (797) (795) (793)
Net cash provided by (used in) financing activities (16,119) 10,251 (103,799)
Net increase (decrease) in cash (6) 1 9
Cash at beginning of year 55 54 45
Cash at end of year $ 49 $ 55 $ 54
v3.25.4
Organization and Description of Business
 12 Months Ended
Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Organization and Description of Business ORGANIZATION AND DESCRIPTION OF BUSINESS
Martin Midstream Partners L.P. (the "Partnership") is a publicly traded limited partnership with a diverse set of operations focused primarily in the Gulf Coast region of the U.S. Its four primary business lines include: terminalling, processing, and storage services for petroleum products and by-products; land and marine transportation services for petroleum products and by-products, chemicals, and specialty products; sulfur and sulfur-based products processing, manufacturing, marketing and distribution; and marketing, distribution, and transportation services for natural gas liquids ("NGL") and blending and packaging services for specialty lubricants and grease.

    The Partnership provides specialty services to major and independent oil and gas companies, independent refiners, large chemical companies, and other wholesale purchasers of certain petroleum products and by-products, with significant business concentrated around the U.S. Gulf Coast refinery complex, which is a major hub for petroleum refining, natural gas gathering and processing, and support services for the exploration and production industry. The petroleum products and by-products the Partnership gathers, transports, stores and markets are produced primarily by major and independent oil and gas companies who often rely on third parties, such as the Partnership, for the transportation and disposition of these products.
    Martin Resource Management Corporation indirectly owns, through its wholly owned subsidiary, Martin Resource LLC, 100% of MMGP Holdings, LLC ("Holdings"), which is the sole member of Martin Midstream GP LLC ("MMGP"), the general partner of the Partnership. As a result, Martin Resource Management Corporation indirectly owns 100% of MMGP.
v3.25.4
Significant Accounting Policies and Practices
 12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Significant Accounting Policies and Practices SIGNIFICANT ACCOUNTING POLICIES AND PRACTICES
(a)       Principles of Presentation and Consolidation

    The consolidated financial statements include the financial statements of the Partnership and its wholly owned subsidiaries and equity method investees. In the opinion of the management of the Partnership’s general partner, all adjustments and elimination of significant intercompany balances necessary for a fair presentation of the Partnership’s results of operations, financial position and cash flows for the periods shown have been made. All such adjustments are of a normal recurring nature. In addition, the Partnership evaluates its relationships with other entities to identify whether they are variable interest entities under certain provisions of the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC"), 810-10 and to assess whether it is the primary beneficiary of such entities. If the determination is made that the Partnership is the primary beneficiary, then that entity is included in the consolidated financial statements in accordance with ASC 810-10. No such variable interest entities existed as of December 31, 2025 or 2024.

    (b)       Product Exchanges
 
The Partnership enters into product exchange agreements with third parties, whereby the Partnership agrees to exchange NGLs and sulfur with third parties. The Partnership records the balance of exchange products due to other companies under these agreements at quoted market product prices and the balance of exchange products due from other companies at the lower of cost or market. Cost is determined using the first-in, first-out ("FIFO") method. Product exchanges with the same counterparty are entered into in contemplation of one another and are combined. The net amount related to location differentials is reported in "Product sales" or "Cost of products sold" in the Consolidated Statements of Operations.
 
(c)       Inventories
 
Inventories are stated at the lower of cost or net realizable value. NGLs, sulfur, and all other inventories not otherwise specified are accounted for using the FIFO method. Lubricants, greases, and lubricant packaging inventories are accounted for using standard cost, which approximates actual cost. Fertilizer inventories are accounted for using weighted average cost, which approximates actual cost.
(d)      Revenue Recognition
 
Terminalling and Storage – Revenue is recognized for storage contracts based on the contracted monthly tank fixed fee. For throughput contracts, revenue is recognized based on the volume moved through the Partnership’s terminals at the contracted rate. For storage and throughput contracts at the Partnership's underground NGL storage facility, revenue is recognized based on the volume stored and moved through the facility at the contracted rate. For the Partnership’s tolling agreement, revenue is recognized based on the contracted monthly reservation fee and throughput volumes moved through the facility.  

Transportation – Revenue related to land transportation is recognized for line hauls based on a mileage rate. For contracted trips, revenue is recognized upon completion of the particular trip. The performance of the service is invoiced as the transaction occurs and is generally paid within a month. Revenue related to marine transportation is recognized for time charters based on a per day rate. For contracted trips, revenue is recognized upon completion of the particular trip. The performance of the service is invoiced as the transaction occurs and is generally paid within a month.

Sulfur Services – Revenue from sulfur and fertilizer product sales is recognized when the customer takes title to the product. Delivery of the product is invoiced as the transaction occurs and is generally paid within a month. Revenue from sulfur services is recognized as services are performed during each monthly period. The performance of the service is invoiced as the transaction occurs and is generally paid within a month.

Specialty Products – NGL revenue is recognized when title is transferred, which is generally when the product is delivered by truck, rail, or pipeline to the Partnership's NGL customers or when the customer picks up the product from our facilities. When lubricants are sold by truck or rail, revenue is recognized when title is transferred, which is generally when the product leaves the Partnership's facility, but can vary based on the specific terms of the contract. The product is invoiced as the transaction occurs and is generally paid within a month.

(e)       Equity Method Investments
 
The Partnership uses the equity method of accounting for investments in unconsolidated entities where the ability to exercise significant influence over such entities exists. Investments in unconsolidated entities consist of capital contributions and advances plus the Partnership’s share of accumulated earnings as of the entities’ latest fiscal year-ends, less capital withdrawals and distributions. Equity method investments are subject to impairment under the provisions of ASC 323-10, which relates to the equity method of accounting for investments in common stock. No portion of the net income from these entities is included in the Partnership’s operating income.

    (f)      Property, Plant, and Equipment

Owned property, plant, and equipment is stated at cost, less accumulated depreciation. Owned buildings and equipment are depreciated using the straight-line method over the estimated lives of the respective assets.

Equipment under finance leases is stated at the present value of minimum lease payments less accumulated amortization. Equipment under finance leases is amortized on a straight-line basis over the estimated useful life of the asset.

Routine maintenance and repairs are charged to expense while costs of betterments and renewals are capitalized. When an asset is retired or sold, its cost and related accumulated depreciation are removed from the accounts, and the difference between net book value of the asset and proceeds from disposition is recognized as gain or loss.
 
(g)      Goodwill and Other Intangible Assets

Goodwill is subject to a fair-value based impairment test on an annual basis, or more often if events or circumstances indicate there may be impairment. The Partnership is required to identify its reporting units and determine the carrying value of each reporting unit by assigning the assets and liabilities, including the existing goodwill and intangible assets. The Partnership is required to determine the fair value of each reporting unit and compare it to the carrying amount of the reporting unit. To the extent the carrying amount of a reporting unit exceeds the fair value of the reporting unit, the Partnership will record the amount of goodwill impairment as the excess of a reporting unit's carrying amount over its fair value, not to exceed the total amount of goodwill allocated to the reporting unit.
    When assessing the recoverability of goodwill and other intangible assets, the Partnership may first assess qualitative factors in determining whether it is more likely than not that the fair value of a reporting unit or other intangible asset is less than its carrying amount. After assessing qualitative factors, if the Partnership determines that it is not more likely than not that the fair value of a reporting unit or other intangible asset is less than its carrying amount, then performing a quantitative assessment is not required. If an initial qualitative assessment indicates that it is more likely than not the carrying amount exceeds the fair value of a reporting unit or other intangible asset, a quantitative analysis will be performed. The Partnership may also elect to bypass the qualitative assessment and proceed directly to a quantitative analysis depending on the facts and circumstances.

Of the Partnership's four reporting units, the terminalling and storage, transportation, specialty products and sulfur services reporting units all contain goodwill.

    In performing a quantitative analysis, recoverability of goodwill for each reporting unit is measured using a weighting of the discounted cash flow method and two market approaches (the guideline public company method and the guideline transaction method). The discounted cash flow model incorporates discount rates commensurate with the risks involved. Use of a discounted cash flow model is common practice in assessing impairment in the absence of available transactional market evidence to determine the fair value. The key assumptions used in the discounted cash flow valuation model include discount rates, growth rates, cash flow projections and terminal value rates. Discount rates, growth rates and cash flow projections are the most sensitive and susceptible to change as they require significant management judgment. Discount rates are determined by using a weighted average cost of capital ("WACC"). The WACC considers market and industry data as well as company-specific risk factors for each reporting unit in determining the appropriate discount rate to be used. The discount rate utilized for each reporting unit is indicative of the return an investor would expect to receive for investing in such a business. Management, considering industry and company specific historical and projected data, develops growth rates and cash flow projections for each reporting unit. Terminal value rate determination follows common methodology of capturing the present value of perpetual cash flow estimates beyond the last projected period assuming a constant WACC and low long-term growth rates. If the calculated fair value is less than the current carrying amount, the Partnership will record the amount of goodwill impairment as the excess of a reporting unit's carrying amount over its fair value, not to exceed the total amount of goodwill allocated to the reporting unit.

Significant changes in these estimates and assumptions could materially affect the determination of fair value for each reporting unit which could give rise to future impairment. Changes to these estimates and assumptions can include, but may not be limited to, varying commodity prices, volume changes and operating costs due to market conditions and/or alternative providers of services.

Based upon the most recent annual review as of August 31, 2025, no goodwill impairment exists within the Partnership's reporting units for the year ended December 31, 2025. No goodwill impairment was recorded for the years ended December 31, 2024 or 2023.

Other intangible assets that have finite lives are tested for impairment when events or circumstances indicate that the carrying value may not be recoverable. An impairment is indicated if the carrying amount of a long-lived intangible asset exceeds the sum of the undiscounted future cash flows expected to result from the use and eventual disposition of the asset. If impairment is indicated, the Partnership would record an impairment loss equal to the difference between the carrying value and the fair value of the asset. There were no intangible asset impairments for the years ended December 31, 2025, 2024 or 2023.
 
(h)      Debt Issuance Costs

Debt issuance costs relating to the Partnership’s credit facility and senior notes are deferred and amortized over the terms of the debt arrangements and are shown, net of accumulated amortization, as a reduction of the related long-term debt.

In connection with the issuance, amendment, expansion and restatement of debt arrangements, the Partnership incurred debt issuance costs of $808, $23 and $14,289 in the years ended December 31, 2025, 2024 and 2023, respectively.

Amortization and write-off of debt issuance costs, which is included in interest expense, totaled $3,280, $3,085 and $3,978 for the years ended December 31, 2025, 2024 and 2023, respectively. Accumulated amortization amounted to $35,677 and $32,397 at December 31, 2025 and 2024, respectively.
 
(i)      Impairment of Long-Lived Assets
 
In accordance with ASC 360-10, long-lived assets, such as property, plant and equipment, and intangible assets with definite lives are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be disposed of would be separately presented in the balance sheet and reported at the lower of the carrying amount or fair value less costs to sell and would no longer be depreciated. The assets and liabilities of a disposed group classified as held for sale would be presented separately in the appropriate asset and liability sections of the balance sheet.  
    
(j)      Asset Retirement Obligations
Under ASC 410-20, which relates to accounting requirements for costs associated with legal obligations to retire tangible, long-lived assets, the Partnership records an asset retirement obligation at present value based upon estimated costs to retire the asset in the period in which it is incurred by increasing the carrying amount of the related long-lived asset. In each subsequent period, the liability is accreted over time towards the ultimate obligation amount and the capitalized costs are depreciated over the useful life of the related asset.  

(k) Use of Estimates

Management has made a number of estimates and assumptions relating to the reporting of assets and liabilities and the disclosure of contingent assets and liabilities to prepare these consolidated financial statements in conformity with accounting principles generally accepted in the U.S. Actual results could differ from those estimates.
 
(l)      Environmental Liabilities and Litigation
 
The Partnership’s policy is to accrue for losses associated with environmental remediation obligations when such losses are probable and reasonably estimable. Accruals for estimated losses from environmental remediation obligations generally are recognized no later than completion of the remedial feasibility study. Such accruals are adjusted as further information develops or circumstances change. Costs of future expenditures for environmental remediation obligations are not discounted to their present value. Recoveries of environmental remediation costs from other parties are recorded as assets when their receipt is deemed probable.
 
(m)      Trade and Accrued Accounts Receivable and Allowance for Doubtful Accounts
 
Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The allowance for doubtful accounts is the Partnership’s best estimate of the amount of probable credit losses in the Partnership’s existing accounts receivable.
 
(n)      Deferred Catalyst Costs

The cost of the periodic replacement of catalysts is deferred and amortized over the catalyst’s estimated useful life, which ranges from 12 to 36 months.

(o)      Deferred Turnaround Costs

The Partnership capitalizes the cost of major turnarounds and amortizes these costs over the estimated period to the next turnaround, which ranges from 12 to 36 months.
(p)      Income Taxes
 
The Partnership is subject to the Texas margin tax, which is considered a state income tax, and is included in income tax expense on the Consolidated Statements of Operations. Since the tax base on the Texas margin tax is derived from an income-based measure, the margin tax is construed as an income tax and, therefore, the recognition of deferred taxes applies to the margin tax. The impact on deferred taxes as a result of this provision is immaterial.

The Partnership's financial statements recognize the current and deferred income tax consequences that result from the activities of its wholly owned C-Corporation subsidiary, Martin Transport, Inc. ("MTI"), during the current period pursuant to the provisions of the FASB ASC 740 related to income taxes. As a result of the common control transaction with the Partnership, the deferred tax consequences of the changes in the tax bases of MTI’s assets and liabilities were included in equity under the provisions of ASC 740-20-45-11.

With respect to MTI, income taxes are accounted for under the asset and liability method, whereby deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date.

In the ordinary course of business, there may be many transactions and calculations where the ultimate tax outcome is uncertain. The calculation of tax liabilities involves dealing with uncertainties in the application of complex tax laws. In accordance with the provisions of ASC 740, we use a two-step approach for recognizing and measuring tax benefits taken or expected to be taken in a tax return. In the first step, “recognition”, the Partnership determines whether it is more likely than not that a tax position will be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. In evaluating whether a tax position has met the more-likely-than-not recognition threshold, the Partnership presumes that the position will be examined by the appropriate taxing authority that has full knowledge of all relevant information. In the second step, “measurement”, a tax position that meets the more-likely-than-not threshold is measured to determine the amount of benefit to recognize in the financial statements. The tax position is measured at the largest amount of benefit that is greater than 50 percent likely of being realized upon ultimate settlement based upon management’s intent regarding negotiation and litigation. In evaluating all income tax positions for all open years, management has determined all positions are more likely than not to be sustained at full benefit based upon their technical merit under applicable tax laws.
v3.25.4
Recent Accounting Pronouncements
 12 Months Ended
Dec. 31, 2025
Accounting Changes and Error Corrections [Abstract]  
Recent Accounting Pronouncements RECENT ACCOUNTING PRONOUNCEMENTS
In November 2023, the FASB issued ASU 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures" ("ASU 2023-07"). ASU 2023-07 requires annual and interim disclosures that are expected to improve reportable segment disclosures, primarily through enhanced disclosures about significant segment expenses. The provisions of ASU 2023-07 are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The Partnership adopted ASU 2023-07 and its expanded segment disclosure requirements in compliance with the required adoption guidelines.

In December 2023, the FASB issued ASU 2023-09, “Improvements to Income Tax Disclosures” ("ASU 2023-09"), which requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as additional information on income taxes paid. The provisions of ASU 2023-09 are effective for annual reporting periods beginning after December 15, 2024, with early adoption permitted and can be applied on either a prospective or retroactive basis. The Partnership adopted ASU 2023-09 and its expanded disclosure requirements, on a retrospective basis, in compliance with the required adoption guidelines.
v3.25.4
Exit Activities and Divestitures
 12 Months Ended
Dec. 31, 2025
Discontinued Operations and Disposal Groups [Abstract]  
Exit Activities and Divestitures EXIT ACTIVITIES AND DIVESTITURES
    During the second quarter of 2023, the Partnership completed the exit from its butane optimization business at the conclusion of the butane selling season. This exit did not qualify as discontinued operations in accordance with ASC 205. Going forward, with respect to butane, the Partnership will operate as a fee-based butane logistics business, primarily continuing to utilize its north Louisiana underground storage assets, which have both truck and rail capability. This logistics business utilizes the Partnership's truck transportation assets for fee-based product movements. As a result of this new business model, the Partnership no longer carries butane inventory, reducing commodity risk exposure, cash flow and earnings volatility, and working capital requirements. The following revenues and costs, which are included in the financial results for all periods presented, are not expected to be incurred under the new fee-based butane logistics business model. The butane optimization business has historically been included in the Partnership's Specialty Products operating segment.
202520242023
Products revenue$— $— $70,539 
Cost of products sold— — 72,283 
Selling, general and administrative expenses— — 512 
$— $— $(2,256)
v3.25.4
Revenue
 12 Months Ended
Dec. 31, 2025
Revenue from Contract with Customer [Abstract]  
Revenue REVENUE
    The following table disaggregates our revenue by major source:
202520242023
Terminalling and storage segment
Throughput and storage$90,831 $89,067 $86,514 
$90,831 $89,067 $86,514 
Transportation segment
Land transportation$156,300 $165,353 $166,717 
Inland transportation46,955 51,826 50,890 
Offshore transportation9,254 6,755 6,070 
$212,509 $223,934 $223,677 
Sulfur service segment
Sulfur product sales$38,380 $31,347 $30,170 
Fertilizer product sales109,258 83,852 97,395 
Sulfur services 16,441 14,572 13,430 
$164,079 $129,771 $140,995 
Specialty products segment
Natural gas liquids product sales$139,940 $144,238 $214,713 
Lubricant product sales108,754 120,612 132,064 
$248,694 $264,850 $346,777 
Total revenues$716,113 $707,622 $797,963 

    Revenue is measured based on a consideration specified in a contract with a customer and excludes amounts collected on behalf of third parties where the Partnership is acting as an agent. The Partnership recognizes revenue when the Partnership satisfies a performance obligation, which typically occurs when the Partnership transfers control over a product to a customer or as the Partnership delivers a service.
    The following is a description of the principal activities - separated by reportable segments - from which the Partnership generates revenue.

Terminalling and Storage Segment

    Revenue is recognized for storage contracts based on the contracted monthly tank fixed fee. For throughput contracts, revenue is recognized based on the volume moved through the Partnership’s terminals at the contracted rate. For storage and throughput contracts at the Partnership's underground NGL storage facility, revenue is recognized based on the volume stored and moved through the facility at the contracted rate. For the Partnership’s tolling agreement, revenue is recognized based on the contracted monthly reservation fee and throughput volumes moved through the facility. Throughput and storage revenue in the table above includes non-cancelable revenue arrangements that are under the scope of ASC 842, whereby the Partnership has committed certain Terminalling and Storage assets in exchange for a minimum fee.

Transportation Segment

    Revenue related to land transportation is recognized for line hauls based on a mileage rate. For contracted trips, revenue is recognized upon completion of the particular trip. The performance of the service is invoiced as the transaction occurs and is generally paid within a month.

    Revenue related to marine transportation is recognized for time charters based on a per day rate. For contracted trips, revenue is recognized upon completion of the particular trip. The performance of the service is invoiced as the transaction occurs and is generally paid within a month.

Sulfur Services Segment

    Revenue from sulfur and fertilizer product sales is recognized when the customer takes title to the product. Delivery of product is invoiced as the transaction occurs and is generally paid within a month. Revenue from sulfur services is recognized as services are performed during each monthly period. The performance of the service is invoiced as the transaction occurs and is generally paid within a month.

Specialty Products Segment

    NGL revenue is recognized when title is transferred, which is generally when the product is delivered by truck, rail, or pipeline to the Partnership's NGL customers or when the customer picks up the product from our facilities. When lubricants are sold by truck or rail, revenue is recognized when title is transferred, which is generally when the product leaves the Partnership's facility, but can vary based on the specific terms of the contract. Delivery of product is invoiced as the transaction occurs and is generally paid within a month.

Natural gas liquids product sales for 2023 include $70,539 of revenues attributable to the Partnership’s former butane optimization business, which was exited during the second quarter of 2023 (see Note 4, Exit Activities and Divestitures). Following the exit, the Partnership transitioned to a fee-based butane logistics model and no longer records product sales related to this activity.

    The table below includes estimated minimum revenue expected to be recognized in the future related to performance obligations that are unsatisfied at the end of the reporting period. The Partnership applies the practical expedient in ASC 606-10-50-14(a) and does not disclose information about remaining performance obligations that have original expected durations of one year or less.
20262027202820292030ThereafterTotal
Terminalling and Storage
Throughput and storage$45,672 $47,042 $48,454 $49,907 $51,404 $52,947 $295,426 
Specialty Products
Natural Gas Liquids3,934 — — — — — 3,934 
Sulfur Services
Product sales14,237 14,237 14,237 — — — 42,711 
Service revenues10,384 7,454 6,953 6,953 2,655 36,506 70,905 
Total$74,227 $68,733 $69,644 $56,860 $54,059 $89,453 $412,976 

The Partnership has non-cancelable revenue arrangements that are under the scope of ASC 842 whereby we have committed certain terminalling and storage assets in exchange for a minimum fee. Future minimum revenues the Partnership expects to receive under these non-cancelable arrangements as of December 31, 2025 are as follows: 2026 - $24,173; 2027 - $13,022; 2028 - $12,235; 2029 - $9,909; 2030 - $8,334; subsequent years - $253.
v3.25.4
Inventories
 12 Months Ended
Dec. 31, 2025
Inventory Disclosure [Abstract]  
Inventories INVENTORIES
Components of inventories at December 31, 2025 and 2024 were as follows: 
 20252024
Natural Gas Liquids$1,125 $2,814 
Sulfur1,300 1,440 
Fertilizer21,666 18,463 
Lubricants20,281 23,227 
Other5,876 5,763 
 $50,248 $51,707 
v3.25.4
Property, Plant, and Equipment
 12 Months Ended
Dec. 31, 2025
Property, Plant and Equipment [Abstract]  
Property, Plant, and Equipment PROPERTY, PLANT, AND EQUIPMENT
At December 31, 2025 and 2024, property, plant and equipment consisted of the following:
 Depreciable Lives20252024
Land—$18,812 $18,812 
Improvements to land and buildings
10-25 years
142,035 136,609 
Storage equipment
5-50 years
131,707 130,663 
Marine vessels
4-25 years
201,831 194,406 
Operating plant and equipment
3-50 years
421,088 396,631 
Furniture, fixtures and other equipment
3-20 years
7,629 7,908 
Transportation equipment
3-7 years
39,115 43,807 
Construction in progress 8,536 25,223 
  $970,753 $954,059 

Depreciation expense for the years ended December 31, 2025, 2024 and 2023 was $40,393, $41,604 and $44,700, respectively, which includes amortization of fixed assets acquired under finance lease obligations of $15, $11, and $6. Gross assets under finance leases were $77 and $77 at December 31, 2025 and 2024, respectively. Accumulated amortization associated with finance leases was $26 and $10 at December 31, 2025 and 2024, respectively.

Additions to property, plant and equipment included in accounts payable at December 31, 2025, 2024 and 2023 were $2,146, $2,661, and $2,943, respectively. No equipment was purchased under finance lease obligations for the years ended December 31, 2025, 2024, and 2023.
v3.25.4
Goodwill
 12 Months Ended
Dec. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill GOODWILL
    The following table represents the goodwill balance by reporting unit at December 31, 2025 and 2024 as follows:
20252024
Carrying amount of goodwill:
Terminalling and storage$6,756 $6,756 
Specialty products4,229 4,229 
Sulfur services 5,197 5,197 
Transportation489 489 
        Total goodwill$16,671 $16,671 
v3.25.4
Leases
 12 Months Ended
Dec. 31, 2025
Leases [Abstract]  
Leases LEASES
    The Partnership has numerous operating leases primarily for terminal facilities and transportation and other equipment. The leases generally provide that all expenses related to the equipment are to be paid by the lessee.

    Operating lease right of use ("ROU") assets and operating lease liabilities are recognized based on the present value of lease payments over the lease term at commencement date. Because most of the Partnership's leases do not provide an implicit rate of return, the Partnership uses its imputed collateralized rate based on the information available at commencement date in determining the present value of lease payments. The estimated rate is based on a risk-free rate plus a risk-adjusted margin.

The Partnership's leases have remaining lease terms of 1 year to 11 years, some of which include options to extend the leases for up to 5 years, and some of which include options to terminate the leases within 1 year. The Partnership includes extension periods and excludes termination periods from its lease term if, at commencement, it is reasonably likely that the Partnership will exercise the option.

    The components of lease expense for the years ended December 31, 2025, 2024, and 2023 were as follows:
202520242023
Operating lease cost$26,747 $22,256 $16,198 
Finance lease cost:
     Amortization of right-of-use assets15 11 6 
     Interest on lease liabilities4 3 — 
Short-term lease cost5,691 4,748 5,415 
Variable lease cost100 163 191 
Total lease cost$32,557 $27,181 $21,810 
    Supplemental cash flow information for the years ended December 31, 2025, 2024, and 2023 related to leases were as follows:
202520242023
Cash paid for amounts included in the measurement of lease liabilities:
     Operating cash flows from operating leases$48,374 $39,763 $29,820 
     Operating cash flows from finance leases4 3 — 
     Financing cash flows from finance leases14 9 9 
Right-of-use assets obtained in exchange for lease obligations:
     Operating leases$23,402 $21,133 $38,935 
     Finance leases— 77 — 
    
Supplemental balance sheet information related to leases was as follows at December 31, 2025 and 2024:
20252024
Operating Leases
Operating lease right-of-use assets$69,938 $67,140 
Current portion of operating lease liabilities included in "Other accrued liabilities"$22,043 $19,707 
Operating lease liabilities48,353 47,815 
     Total operating lease liabilities$70,396 $67,522 
Finance Leases
Property, plant and equipment, at cost$77 $77 
Accumulated depreciation(26)(10)
     Property, plant and equipment, net$51 $67 
Current installments of finance lease obligations$15 $14 
Finance lease obligations$39 $55 
     Total finance lease obligations$54 $69 
Weighted Average Remaining Lease Term (years)
     Operating leases3.794.07
     Finance leases3.324.32
Weighted Average Discount Rate
     Operating leases7.56 %7.28 %
     Finance leases7.00 %7.00 %
    The Partnership’s future minimum lease obligations as of December 31, 2025 consist of the following:
Operating LeasesFinance Leases
Year 1$28,017 $18 
Year 222,881 18 
Year 315,882 18 
Year 49,482 6 
Year 54,743 — 
Thereafter2,991 — 
     Total83,996 60 
     Less amounts representing interest costs(13,600)(6)
Total lease liability$70,396 $54 
Leases LEASES
    The Partnership has numerous operating leases primarily for terminal facilities and transportation and other equipment. The leases generally provide that all expenses related to the equipment are to be paid by the lessee.

    Operating lease right of use ("ROU") assets and operating lease liabilities are recognized based on the present value of lease payments over the lease term at commencement date. Because most of the Partnership's leases do not provide an implicit rate of return, the Partnership uses its imputed collateralized rate based on the information available at commencement date in determining the present value of lease payments. The estimated rate is based on a risk-free rate plus a risk-adjusted margin.

The Partnership's leases have remaining lease terms of 1 year to 11 years, some of which include options to extend the leases for up to 5 years, and some of which include options to terminate the leases within 1 year. The Partnership includes extension periods and excludes termination periods from its lease term if, at commencement, it is reasonably likely that the Partnership will exercise the option.

    The components of lease expense for the years ended December 31, 2025, 2024, and 2023 were as follows:
202520242023
Operating lease cost$26,747 $22,256 $16,198 
Finance lease cost:
     Amortization of right-of-use assets15 11 6 
     Interest on lease liabilities4 3 — 
Short-term lease cost5,691 4,748 5,415 
Variable lease cost100 163 191 
Total lease cost$32,557 $27,181 $21,810 
    Supplemental cash flow information for the years ended December 31, 2025, 2024, and 2023 related to leases were as follows:
202520242023
Cash paid for amounts included in the measurement of lease liabilities:
     Operating cash flows from operating leases$48,374 $39,763 $29,820 
     Operating cash flows from finance leases4 3 — 
     Financing cash flows from finance leases14 9 9 
Right-of-use assets obtained in exchange for lease obligations:
     Operating leases$23,402 $21,133 $38,935 
     Finance leases— 77 — 
    
Supplemental balance sheet information related to leases was as follows at December 31, 2025 and 2024:
20252024
Operating Leases
Operating lease right-of-use assets$69,938 $67,140 
Current portion of operating lease liabilities included in "Other accrued liabilities"$22,043 $19,707 
Operating lease liabilities48,353 47,815 
     Total operating lease liabilities$70,396 $67,522 
Finance Leases
Property, plant and equipment, at cost$77 $77 
Accumulated depreciation(26)(10)
     Property, plant and equipment, net$51 $67 
Current installments of finance lease obligations$15 $14 
Finance lease obligations$39 $55 
     Total finance lease obligations$54 $69 
Weighted Average Remaining Lease Term (years)
     Operating leases3.794.07
     Finance leases3.324.32
Weighted Average Discount Rate
     Operating leases7.56 %7.28 %
     Finance leases7.00 %7.00 %
    The Partnership’s future minimum lease obligations as of December 31, 2025 consist of the following:
Operating LeasesFinance Leases
Year 1$28,017 $18 
Year 222,881 18 
Year 315,882 18 
Year 49,482 6 
Year 54,743 — 
Thereafter2,991 — 
     Total83,996 60 
     Less amounts representing interest costs(13,600)(6)
Total lease liability$70,396 $54 
Leases LEASES
    The Partnership has numerous operating leases primarily for terminal facilities and transportation and other equipment. The leases generally provide that all expenses related to the equipment are to be paid by the lessee.

    Operating lease right of use ("ROU") assets and operating lease liabilities are recognized based on the present value of lease payments over the lease term at commencement date. Because most of the Partnership's leases do not provide an implicit rate of return, the Partnership uses its imputed collateralized rate based on the information available at commencement date in determining the present value of lease payments. The estimated rate is based on a risk-free rate plus a risk-adjusted margin.

The Partnership's leases have remaining lease terms of 1 year to 11 years, some of which include options to extend the leases for up to 5 years, and some of which include options to terminate the leases within 1 year. The Partnership includes extension periods and excludes termination periods from its lease term if, at commencement, it is reasonably likely that the Partnership will exercise the option.

    The components of lease expense for the years ended December 31, 2025, 2024, and 2023 were as follows:
202520242023
Operating lease cost$26,747 $22,256 $16,198 
Finance lease cost:
     Amortization of right-of-use assets15 11 6 
     Interest on lease liabilities4 3 — 
Short-term lease cost5,691 4,748 5,415 
Variable lease cost100 163 191 
Total lease cost$32,557 $27,181 $21,810 
    Supplemental cash flow information for the years ended December 31, 2025, 2024, and 2023 related to leases were as follows:
202520242023
Cash paid for amounts included in the measurement of lease liabilities:
     Operating cash flows from operating leases$48,374 $39,763 $29,820 
     Operating cash flows from finance leases4 3 — 
     Financing cash flows from finance leases14 9 9 
Right-of-use assets obtained in exchange for lease obligations:
     Operating leases$23,402 $21,133 $38,935 
     Finance leases— 77 — 
    
Supplemental balance sheet information related to leases was as follows at December 31, 2025 and 2024:
20252024
Operating Leases
Operating lease right-of-use assets$69,938 $67,140 
Current portion of operating lease liabilities included in "Other accrued liabilities"$22,043 $19,707 
Operating lease liabilities48,353 47,815 
     Total operating lease liabilities$70,396 $67,522 
Finance Leases
Property, plant and equipment, at cost$77 $77 
Accumulated depreciation(26)(10)
     Property, plant and equipment, net$51 $67 
Current installments of finance lease obligations$15 $14 
Finance lease obligations$39 $55 
     Total finance lease obligations$54 $69 
Weighted Average Remaining Lease Term (years)
     Operating leases3.794.07
     Finance leases3.324.32
Weighted Average Discount Rate
     Operating leases7.56 %7.28 %
     Finance leases7.00 %7.00 %
    The Partnership’s future minimum lease obligations as of December 31, 2025 consist of the following:
Operating LeasesFinance Leases
Year 1$28,017 $18 
Year 222,881 18 
Year 315,882 18 
Year 49,482 6 
Year 54,743 — 
Thereafter2,991 — 
     Total83,996 60 
     Less amounts representing interest costs(13,600)(6)
Total lease liability$70,396 $54 
v3.25.4
Fair Value Measurements
 12 Months Ended
Dec. 31, 2025
Fair Value Disclosures [Abstract]  
Fair Value Measurements FAIR VALUE MEASUREMENTS
    The Partnership uses a valuation framework based upon inputs that market participants use in pricing certain assets and liabilities. These inputs are classified into two categories: observable inputs and unobservable inputs. Observable inputs represent market data obtained from independent sources. Unobservable inputs represent the Partnership's own market assumptions. Unobservable inputs are used only if observable inputs are unavailable or not reasonably available without undue cost and effort. The two types of inputs are further prioritized into the following hierarchy:

Level 1: Quoted market prices in active markets for identical assets or liabilities.
Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data.
Level 3: Unobservable inputs that reflect the entity's own assumptions and are not corroborated by market data.

There were no assets and liabilities measured at fair value on a recurring basis as of December 31, 2025 or 2024.

    The Partnership is required to disclose estimated fair values for its financial instruments. Fair value estimates are set forth below for these financial instruments. The following methods and assumptions were used to estimate the fair value of each class of financial instrument:

•Accounts and other receivables, trade and other accounts payable, accrued interest payable, other accrued liabilities, income taxes payable and due from/to affiliates: The carrying amounts approximate fair value due to the short maturity and highly liquid nature of these instruments, and as such these have been excluded from the table below. There is negligible credit risk associated with these instruments.

•Current and non-current portion of long-term debt: The carrying amount of the credit facility approximates fair value due to the debt having a variable interest rate and is in Level 2. The estimated fair value of the 2028 Notes is considered Level 2, as the fair value is based upon quoted prices for identical liabilities in markets that are not active.
December 31, 2025December 31, 2024
Carrying
Value		Fair
Value		Carrying
Value		Fair
Value
2028 Notes390,795 415,726 386,377 436,172 
Total$390,795 $415,726 $386,377 $436,172 
v3.25.4
Related Party Transactions
 12 Months Ended
Dec. 31, 2025
Related Party Transactions [Abstract]  
Related Party Transactions RELATED PARTY TRANSACTIONS
As of December 31, 2025, Martin Resource Management Corporation owned 7,874,446 of the Partnership’s common units representing approximately 20.2% of the Partnership’s outstanding limited partnership units. Martin Resource Management Corporation controls the Partnership's general partner by virtue of owning 100% of the membership interests in
Holdings, the sole member of the Partnership's general partner. The Partnership’s general partner, MMGP, owns a 2% general partner interest in the Partnership. The Partnership’s general partner’s ability, as general partner, to manage and operate the Partnership, and Martin Resource Management Corporation’s ownership as of December 31, 2025 of approximately 20.2% of the Partnership’s outstanding limited partnership units, effectively gives Martin Resource Management Corporation the ability to veto some of the Partnership’s actions and to control the Partnership’s management.
 
    The following is a description of the Partnership’s material related party agreements:
 
Omnibus Agreement
 
              Omnibus Agreement.  The Partnership and its general partner are parties to the Omnibus Agreement dated November 1, 2002, with Martin Resource Management Corporation that governs, among other things, potential competition and indemnification obligations among the parties to the agreement, related party transactions, the provision of general administration and support services by Martin Resource Management Corporation and the Partnership’s use of certain Martin Resource Management Corporation trade names and trademarks. The Omnibus Agreement was amended on November 25, 2009, to include processing crude oil into finished products including naphthenic lubricants, distillates, asphalt and other intermediate cuts. The Omnibus Agreement was amended further on October 1, 2012, to permit the Partnership to provide certain lubricant packaging products and services to Martin Resource Management Corporation. The Omnibus Agreement was amended further on October 17, 2023 to include lubricants and packing in the Partnership’s definition of business.

    Non-Competition Provisions. Martin Resource Management Corporation has agreed for so long as it controls the general partner of the Partnership, not to engage in the business of:

•providing terminalling and storage services for petroleum products and by-products including the refining, blending and packaging of finished lubricants;

•providing land and marine transportation of petroleum products, by-products, and chemicals; and

•manufacturing and selling sulfur-based fertilizer products and other sulfur-related products.

    This restriction does not apply to:

•the ownership and/or operation on the Partnership’s behalf of any asset or group of assets owned by it or its affiliates;

•any business operated by Martin Resource Management Corporation, including the following:

◦distributing asphalt, marine fuel and other liquids;

◦providing shore-based marine services in Texas, Louisiana, Mississippi, and Alabama;

◦operating a crude oil gathering business in Stephens, Arkansas;

◦providing crude oil gathering and marketing services of base oils, asphalt, and distillate products in Smackover, Arkansas;

◦providing crude oil marketing and transportation from the well head to the end market;

◦operating an environmental consulting company;

◦operating a butane optimization business;

◦supplying employees and services for the operation of the Partnership's business; and

◦operating, solely for our account, the asphalt facilities owned by the Partnership in each of Hondo, South Houston and Port Neches, Texas and Omaha, Nebraska.
•any business that Martin Resource Management Corporation acquires or constructs that has a fair market value of less than $5,000;

•any business that Martin Resource Management Corporation acquires or constructs that has a fair market value of $5,000 or more if the Partnership has been offered the opportunity to purchase the business for fair market value and the Partnership declines to do so with the concurrence of the Conflicts Committee; and

•any business that Martin Resource Management Corporation acquires or constructs where a portion of such business includes a restricted business and the fair market value of the restricted business is $5,000 or more and represents less than 20% of the aggregate value of the entire business to be acquired or constructed; provided that, following completion of the acquisition or construction, the Partnership will be provided the opportunity to purchase the restricted business.
    
    Services.  Under the Omnibus Agreement, Martin Resource Management Corporation provides the Partnership with corporate staff, support services, and administrative services necessary to operate the Partnership’s business. The Omnibus Agreement requires the Partnership to reimburse Martin Resource Management Corporation for all direct expenses it incurs or payments it makes on the Partnership’s behalf or in connection with the operation of the Partnership’s business. There is no monetary limitation on the amount the Partnership is required to reimburse Martin Resource Management Corporation for direct expenses. In addition to the direct expenses, under the Omnibus Agreement, the Partnership is required to reimburse Martin Resource Management Corporation for indirect general and administrative and corporate overhead expenses.

    Effective January 1, 2024, through December 31, 2025, the Board of Directors approved an annual reimbursement amount for indirect expenses of $13,536. The Partnership reimbursed Martin Resource Management Corporation for $13,536, $13,508 and $13,982 of indirect expenses for the years ended December 31, 2025, 2024 and 2023, respectively. The Board of Directors will review and approve future adjustments in the reimbursement amount for indirect expenses, if any, annually.

    These indirect expenses are intended to cover the centralized corporate functions Martin Resource Management Corporation provides to the Partnership, such as accounting, treasury, clerical, engineering, legal, billing, information technology, administration of insurance, general office expenses and employee benefit plans and other general corporate overhead functions the Partnership shares with Martin Resource Management Corporation retained businesses. The provisions of the Omnibus Agreement regarding Martin Resource Management Corporation’s services will terminate if Martin Resource Management Corporation ceases to control the general partner of the Partnership.

    Related Party Transactions. The Omnibus Agreement prohibits the Partnership from entering into any material agreement with Martin Resource Management Corporation without the prior approval of the Conflicts Committee. For purposes of the Omnibus Agreement, the term "material agreements" means any agreement between the Partnership and Martin Resource Management Corporation that requires aggregate annual payments in excess of the then-applicable agreed upon reimbursable amount of indirect general and administrative expenses. Please read "Services" above.

    License Provisions. Under the Omnibus Agreement, Martin Resource Management Corporation has granted the Partnership a nontransferable, nonexclusive, royalty-free right and license to use certain of its trade names and marks, as well as the trade names and marks used by some of its affiliates.

    Amendment and Termination. The Omnibus Agreement may be amended by written agreement of the parties; provided, however, that it may not be amended without the approval of the Conflicts Committee if such amendment would adversely affect the unitholders. The Omnibus Agreement was first amended on November 25, 2009, to permit the Partnership to provide refining services to Martin Resource Management Corporation. The Omnibus Agreement was amended further on October 1, 2012, to permit the Partnership to provide certain lubricant packaging products and services to Martin Resource Management Corporation. The Omnibus Agreement was amended further on October 17, 2023 to include lubricants and packaging in the Partnership’s definition of business. Such amendments were approved by the Conflicts Committee. The Omnibus Agreement, other than the indemnification provisions and the provisions limiting the amount for which the Partnership will reimburse Martin Resource Management Corporation for general and administrative services performed on its behalf, will terminate if the Partnership is no longer an affiliate of Martin Resource Management Corporation.
Master Transportation Services Agreement

    Master Transportation Services Agreement.  MTI, a wholly owned subsidiary of the Partnership, is a party to a master transportation services agreement effective January 1, 2019, with certain wholly owned subsidiaries of Martin Resource Management Corporation. Under the agreement, MTI agreed to transport Martin Resource Management Corporation's petroleum products and by-products.

    Term and Pricing.  The agreement will continue unless either party terminates the agreement by giving at least 30 days' written notice to the other party. The rates under the agreement are subject to any adjustments which are mutually agreed upon or in accordance with a price index. Additionally, shipping charges are also subject to fuel surcharges determined on a weekly basis in accordance with the U.S. Department of Energy’s national diesel price list.

    Indemnification.  MTI has agreed to indemnify Martin Resource Management Corporation against all claims arising out of the negligence or willful misconduct of MTI and its officers, employees, agents, representatives and subcontractors. Martin Resource Management Corporation has agreed to indemnify MTI against all claims arising out of the negligence or willful misconduct of Martin Resource Management Corporation and its officers, employees, agents, representatives and subcontractors. In the event a claim is the result of the joint negligence or misconduct of MTI and Martin Resource Management Corporation, indemnification obligations will be shared in proportion to each party’s allocable share of such joint negligence or misconduct.

Terminal Services Agreements

    Diesel Fuel Terminal Services Agreement.  Effective October 1, 2022, The Partnership entered into a third amended and restated terminalling services agreement under which it provides terminal services to Martin Energy Services LLC (“MES”), a wholly owned subsidiary of Martin Resource Management Corporation, for fuel distribution utilizing marine shore-based terminals owned by the Partnership. This agreement amended the existing arrangement between the Partnership and MES by eliminating any minimum throughput volume requirements and increasing the per gallon throughput fee. The term of this agreement expired on December 31, 2023 but will continue on a year-to-year basis until terminated by either party by giving at least 90 days’ written notice prior to the end of any term. Effective January 1, 2024, this agreement was amended to increase the throughput rate and to establish a minimum throughput volume.

    Miscellaneous Terminal Services Agreements.  The Partnership is currently party to several terminal services agreements and from time to time the Partnership may enter into other terminal service agreements for the purpose of providing terminal services to related parties. Individually, each of these agreements is immaterial but when considered in the aggregate they could be deemed material. These agreements are throughput based with a minimum volume commitment. Generally, the fees due under these agreements are adjusted annually based on a price index.

Marine Agreements

    Marine Transportation Agreement. The Partnership is a party to a marine transportation agreement effective January 1, 2006, as amended, under which the Partnership provides marine transportation services to Martin Resource Management Corporation on a spot-contract basis at applicable market rates. Effective each January 1, this agreement automatically renews for consecutive one-year periods unless either party terminates the agreement by giving written notice to the other party at least 60 days prior to the expiration of the then applicable term. The fees the Partnership charges Martin Resource Management Corporation are based on applicable market rates.

    Marine Fuel.  The Partnership is a party to an agreement with Martin Resource Management Corporation dated November 1, 2002, under which Martin Resource Management Corporation provides the Partnership with marine fuel from its locations in the Gulf of America at a fixed rate in excess of the Platt's U.S. Gulf Coast Index for #2 Fuel Oil. Under this agreement, the Partnership agreed to purchase all of its marine fuel requirements that occur in the areas serviced by Martin Resource Management Corporation.
Other Agreements

     Cross Tolling Agreement. The Partnership is a party to an amended and restated tolling agreement with Cross Oil Refining and Marketing, Inc. ("Cross") dated October 28, 2014, under which the Partnership processes crude oil into finished products, including naphthenic lubricants, distillates, asphalt and other intermediate cuts for Cross. The tolling agreement expires November 25, 2031. Under this tolling agreement, Cross agreed to process a minimum of 6,500 barrels per day of crude oil at the facility at a fixed price per barrel. Any additional barrels are processed at a modified price per barrel. In addition, Cross agreed to pay a monthly reservation fee and a periodic fuel surcharge fee based on certain parameters specified in the tolling agreement. Further, certain capital improvements, to the extent requested by Cross, are reimbursed through a capital recovery fee. All of these fees (other than the fuel surcharge) are subject to escalation annually based upon an amount equal to two-thirds (2/3) times the change (increase or decrease) in the Consumer Price Index for a specified annual period.

East Texas Mack Leases. MTI leases equipment, including tractors and trailers, from East Texas Mack Sales ("East Texas Mack"). Certain of our directors or officers are owners of East Texas Mack, including entities affiliated with Ruben Martin, who owns approximately 47.2% of the issued and outstanding stock of East Texas Mack. Amounts paid to East Texas Mack for tractor and trailer lease payments and lease residuals for the fiscal years ended December 31, 2025, 2024 and 2023 were approximately $6,721, $4,998, and $3,256, respectively.

Storage and Services Agreement. The Partnership is a party to a storage and services agreement with Martin Butane, a division of Martin Product Sales LLC (a subsidiary of Martin Resource Management Corporation), dated May 1, 2023, under which the Partnership provides storage and other services for NGLs at the Partnership's underground storage facility located in Arcadia, Louisiana. The primary term of the agreement expired on April 30, 2024, but will continue on a year to year basis until terminated by either party by giving at least 90 days’ written notice prior to the end of any term.

Other Miscellaneous Agreements. From time to time the Partnership enters into other miscellaneous agreements with Martin Resource Management Corporation for the provision of other services or the purchase of other goods.

    The tables below summarize the related party transactions that are included in the related financial statement captions on the face of the Partnership’s Consolidated Statements of Operations. The revenues, costs and expenses reflected in these tables are tabulations of the related party transactions that are recorded in the corresponding caption of the Consolidated Statements of Operations and do not reflect a statement of profits and losses for related party transactions.

    The impact of related party revenues from sales of products and services is reflected in the Consolidated Statements of Operations as follows:
Revenues:
202520242023
Terminalling and storage
$72,244 $71,799 $72,138 
Transportation
30,428 33,250 29,276 
Sulfur services— 664 — 
Product sales:
Specialty products578 352 8,547 
Sulfur services
3,665 105 220 
4,243 457 8,767 
$106,915 $106,170 $110,181 

    The impact of related party cost of products sold is reflected in the Consolidated Statements of Operations as follows:
Cost of products sold:
Specialty products$28,626 $31,789 $35,930 
Sulfur services
12,885 11,915 11,182 
Terminalling and storage
— 72 75 
$41,511 $43,776 $47,187 
    The impact of related party operating expenses is reflected in the Consolidated Statements of Operations as follows:
Operating expenses:
Transportation
$81,835 $79,441 $73,866 
Sulfur services
5,609 4,888 5,738 
Terminalling and storage
23,725 22,502 21,247 
$111,169 $106,831 $100,851 

    The impact of related party selling, general and administrative expenses is reflected in the Consolidated Statements of Operations as follows:
Selling, general and administrative:
Transportation
$8,533 $11,218 $8,927 
Specialty products4,240 5,454 4,152 
Sulfur services
3,800 5,427 3,714 
Terminalling and storage
1,100 3,051 780 
Indirect overhead allocation, net of reimbursement
14,025 14,235 14,448 
$31,698 $39,385 $32,021 
v3.25.4
Supplemental Balance Sheet Information
 12 Months Ended
Dec. 31, 2025
Balance Sheet Related Disclosures [Abstract]  
Supplemental Balance Sheet Information SUPPLEMENTAL BALANCE SHEET INFORMATION
    Components of "Intangibles and other assets, net" at December 31, 2025 and 2024 were as follows:
 20252024
Catalyst and turnaround costs$— $254 
Other intangible assets1 26 
Other1,450 1,229 
 $1,451 $1,509 

Other intangible assets consist of technology-based assets.

Amortization expense, included in "Depreciation and amortization" on the Partnership's Consolidated Statements of Operations includes amortization of intangible assets, turnaround expenses, and deferred charges. Aggregate amortization expense was $9,682, $9,050, and $5,006, for the years ended December 31, 2025, 2024 and 2023, respectively.

Estimated amortization expense for the years subsequent to December 31, 2025 are as follows: 2026 - $8,127; 2027 - $32; 2028 - $32; 2029 - $32; 2030 - $8; subsequent years - $0.
Components of "Other accrued liabilities" at December 31, 2025 and 2024 were as follows:
 20252024
Accrued interest$17,838 $17,899 
Asset retirement obligations283 — 
Property and other taxes payable3,968 4,043 
Accrued payroll7,119 5,187 
Operating lease liabilities22,043 19,707 
Other28 44 
 $51,279 $46,880 

The schedule below summarizes the changes in our asset retirement obligations:
 Year Ended December 31,
 20252024
 (In thousands)
Beginning asset retirement obligations$5,313 $5,182 
Revisions to existing liabilities 1
— — 
Accretion expense121 131 
Liabilities settled(117)— 
Ending asset retirement obligations5,317 5,313 
Current portion of asset retirement obligations 2
(283)— 
Long-term portion of asset retirement obligations 3
$5,034 $5,313 

1 Several factors are considered in the annual review process, including inflation rates, current estimates for removal cost, discount rates, and the estimated remaining useful life of the assets.

2 The current portion of asset retirement obligations is included in "Other accrued liabilities" on the Partnership's Consolidated Balance Sheets.

3 The non-current portion of asset retirement obligations is included in "Other long-term obligations" on the Partnership's Consolidated Balance Sheets.
v3.25.4
Long-Term Debt
 12 Months Ended
Dec. 31, 2025
Debt Disclosure [Abstract]  
Long-Term Debt LONG-TERM DEBT
    At December 31, 2025 and 2024, long-term debt consisted of the following:
20252024
$130,000 1 Credit facility at variable interest rate (7.66% 1 weighted average at December 31, 2025), due November 2027 4 secured by substantially all of the Partnership’s assets, net of unamortized debt issuance costs of $1,787 and $2,242, respectively 2
$37,213 $51,258 
$400,000 Senior notes, 11.5% interest, net of unamortized debt issuance costs of $4,205 and $6,223, respectively, including unamortized discount of $5,000 and $7,400, respectively, due February 2028, secured 2,3,4
390,795 386,377 
Total428,008 437,635 
Less: current portion— — 
Total long-term debt, net of current portion$428,008 $437,635 

    1 The interest rate fluctuates based on Adjusted Term SOFR (set on the date of each advance) or the alternate base rate plus an applicable margin. The margin is set every three months. The applicable margin for revolving loans that are SOFR loans currently ranges from 2.75% to 3.75%, and the applicable margin for revolving loans that are alternate base rate loans currently ranges from 1.75% to 2.75%. The applicable margin for SOFR borrowings and alternate base rate borrowings at December 31, 2025 is 3.75% and 2.75%, respectively. The applicable margin for SOFR borrowings and alternate base rate borrowings effective February 23, 2026 is 3.50% and 2.50%, respectively. The credit facility contains various covenants that limit the Partnership’s ability to make distributions; make certain investments and acquisitions; enter into certain agreements; incur indebtedness; sell assets; and make certain amendments to the Partnership's omnibus agreement with Martin Resource Management Corporation (the "Omnibus Agreement").

    2 The Partnership was in compliance with all debt covenants as of December 31, 2025.

On September 24, 2025, Martin Operating Partnership L.P. (the “Operating Partnership”), a wholly owned subsidiary of the Partnership, the Partnership and certain of the Partnership’s other subsidiaries entered into a the Second Amendment with Royal Bank of Canada, as administrative agent and collateral agent, and the lenders party thereto, which amends the Fourth Amended and Restated Credit Agreement, dated effective as of February 8, 2023 (as previously amended, the “Credit Agreement”).

The Partnership entered into the Second Amendment to, among other things:

•extend the maturity date of amounts outstanding and the lenders’ commitments under the Credit Agreement from February 8, 2027 to November 16, 2027;
•decrease the amount available for the Partnership to borrow under the Credit Agreement on a revolving credit basis from $150,000 to $130,000; and
•adjust the financial covenants as described in more detail below:
◦require the Partnership to maintain a minimum Interest Coverage Ratio (as defined in the Credit Agreement) of at least 1.75 to 1.00 for the fiscal quarter ended March 31, 2025 and each fiscal quarter thereafter;
◦require the Partnership to maintain a maximum Total Leverage Ratio (as defined in the Credit Agreement) of not more than 4.50 to 1.00 for the fiscal quarters ended March 31, 2025 and June 30, 2025, and stepping up to 4.75 to 1.00 for the fiscal quarter ended September 30, 2025 and each fiscal quarter thereafter; and
◦require the Partnership to maintain a maximum First Lien Leverage Ratio (as defined in the Credit Agreement) of not more than 1.25 to 1.00 for the fiscal quarter ended March 31, 2025 and each fiscal quarter thereafter.

The Partnership paid cash interest, net of capitalized interest, in the amount of $52,312, $53,449, and $51,607 for the years ended December 31, 2025, 2024 and 2023, respectively. Capitalized interest was $137, $1,153, and $310 for the years ended December 31, 2025, 2024 and 2023, respectively.
As of December 31, 2025, the Partnership had irrevocable letters of credit outstanding totaling $645.
v3.25.4
Partners' Capital (Deficit)
 12 Months Ended
Dec. 31, 2025
Equity [Abstract]  
Partners' Capital (Deficit) PARTNERS' CAPITAL (DEFICIT)
    As of December 31, 2025, partners’ capital consisted of 39,055,086 common limited partner units, representing a 98% partnership interest, and a 2% general partner interest. Martin Resource Management Corporation, through subsidiaries, owned 7,874,446 of the Partnership's common limited partner units representing approximately 20.2% of the Partnership's outstanding common limited partner units. MMGP, the Partnership's general partner, owns the 2% general partner interest.

The Partnership Agreement contains specific provisions for the allocation of net income and losses to each of the partners for purposes of maintaining their respective partner capital accounts.

Impact on Partners' Capital (Deficit) Related to Transactions Between Entities Under Common Control

Under ASC 805, assets and liabilities transferred between entities under common control are accounted for at the historical cost of those entities' ultimate parent, in a manner similar to a pooling of interests. Any difference in the amount paid by the transferee versus the historical cost of the assets transferred is recorded as an adjustment to equity (contribution or distribution) by the transferee. This is in contrast with a business combination between unrelated parties, where assets and liabilities are recorded at their fair values at the acquisition date, with any excess of amounts paid over the fair value representing goodwill. From time to time, the most recent being in 2019, the Partnership has entered into common control acquisitions from Martin Resource Management Corporation. The consideration transferred totaling $552,058 exceeds the historical cost of the net assets received. This excess of the purchase price over the historical cost of the net assets received has resulted in cumulative distributions of $289,019 reflected as reductions to Partners' capital (deficit).

Distributions of Available Cash

The Partnership distributes all of its available cash (as defined in the Partnership Agreement) within 45 days after the end of each quarter to unitholders of record and to the general partner. Available cash is generally defined as all cash and cash equivalents of the Partnership on hand at the end of each quarter less the amount of cash reserves its general partner determines in its reasonable discretion is necessary or appropriate to: (i) provide for the proper conduct of the Partnership’s business; (ii) comply with applicable law, any debt instruments or other agreements; or (iii) provide funds for distributions to unitholders and the general partner for any one or more of the next four quarters, plus all cash on the date of determination of available cash for the quarter resulting from working capital borrowings made after the end of the quarter.

Net Income (Loss) per Unit

The Partnership follows the provisions of the FASB ASC 260-10 related to earnings per share, which addresses the application of the two-class method in determining income per unit for master limited partnerships having multiple classes of securities that may participate in partnership distributions accounted for as equity distributions. Undistributed earnings are allocated to the general partner and limited partners utilizing the contractual terms of the Partnership Agreement. When current period distributions are in excess of earnings, the excess distributions for the period are to be allocated to the general partner and limited partners based on their respective sharing of losses specified in the Partnership Agreement. Additionally, as required under FASB ASC 260-10-45-61A, unvested share-based payments that entitle employees to receive non-forfeitable distributions are considered participating securities, as defined in FASB ASC 260-10-20, for earnings per unit calculations.
For purposes of computing diluted net income per unit, the Partnership uses the more dilutive of the two-class and if-converted methods. Under the if-converted method, the weighted-average number of subordinated units outstanding for the period is added to the weighted-average number of common units outstanding for purposes of computing basic net income per unit and the resulting amount is compared to the diluted net income per unit computed using the two-class method. The following is a reconciliation of net income (loss) allocated to the general partner and limited partners for purposes of calculating net income (loss) attributable to limited partners per unit:
 Years Ended December 31,
 202520242023
   
Net loss$(14,745)$(5,207)$(4,549)
Less general partner’s interest in net loss:
Distributions payable on behalf of general partner interest16 16 16 
General partner interest in undistributed loss(311)(120)(107)
Less loss allocable to unvested restricted units(61)(25)(14)
Limited partners’ interest in net loss$(14,389)$(5,078)$(4,444)

    The following are the unit amounts used to compute the basic and diluted earnings per limited partner unit for the periods presented:
 Years Ended December 31,
 202520242023
Basic weighted average limited partner units outstanding
38,890,039 38,831,355 38,771,657 
Dilutive effect of restricted units issued
— — — 
Total weighted average limited partner diluted units outstanding
38,890,039 38,831,355 38,771,657 

    All outstanding units were included in the computation of diluted earnings per unit and weighted based on the number of days such units were outstanding during the period presented. All common unit equivalents were antidilutive for the years ended December 31, 2025, 2024 and 2023 because the limited partners were allocated a net loss in these periods.
v3.25.4
Unit Based Awards - Long-Term Incentive Plans
 12 Months Ended
Dec. 31, 2025
Share-Based Payment Arrangement [Abstract]  
Unit Based Awards - Long-Term Incentive Plans UNIT BASED AWARDS - LONG-TERM INCENTIVE PLANS
    The Partnership recognizes compensation cost related to unit-based awards to both employees and non-employees in its consolidated financial statements in accordance with certain provisions of ASC 718. Amounts recognized in operating expense and selling, general, and administrative expense in the consolidated financial statements with respect to these plans are as follows:
For the Year Ended December 31,
202520242023
Restricted unit awards
Employees$— $— $— 
Non-employee directors186 187 163 
Phantom unit Awards
Employees2,176 3,070 (177)
Non-employee directors— — — 
   Total unit-based compensation expense$2,362 $3,257 $(14)

    Long-Term Incentive Plans
    
      The Partnership's general partner has long-term incentive plans for employees and directors of the general partner and its affiliates who perform services for the Partnership.

2021 Phantom Unit Plan

On July 21, 2021, the Board of Directors and the Compensation Committee approved the Martin Midstream Partners L.P. 2021 Phantom Unit Plan (the “2021 Plan”), effective as of the same date. The 2021 Plan permits granting the awards of phantom units and phantom unit appreciation rights (collectively, "phantom unit awards") to any employee or non-employee director of the Partnership, including its executive officers. The awards may be time-based or performance-based and will be paid, if at all, in cash.

The award of a phantom unit under the 2021 Plan entitles the participant to a cash payment equal to the value of the phantom unit on the vesting date or dates, which value is the fair market value of a common unit of the Partnership (a “Unit”) on such vesting date or dates. The award of a phantom unit appreciation right entitles the recipient to a cash payment equal to the difference between the value of a phantom unit on the vesting date or dates in excess of the value assigned by the Compensation Committee to the phantom unit as of the grant date. Phantom units and phantom unit appreciation rights granted to participants do not confer upon participants any right to a Unit.

On July 21, 2021, the Compensation Committee approved forms of time-based award agreements for phantom units and phantom unit appreciation rights, both of which awards vest in full on the third anniversary of the grant date. The grant date value of a phantom unit under a phantom unit appreciation right award is equal to the average of the closing price for a Unit during the 20 trading days immediately preceding the grant date of the award.

Generally, vesting of an award is subject to a participant remaining continuously employed with the Partnership through the vesting date. However, if prior to the vesting date (i) a participant is terminated without cause (as defined in the award agreement) or terminates employment after the participant has attained both the age of 65 and ten years of employment (“retirement-eligible”), a prorated portion of the award will vest and be paid in cash no later than the 30th day following such termination date (subject to a six-month delay in payment for certain retirement-eligible participants) or (ii) there is a change in control of the Partnership (as defined in the 2021 Plan), the award will vest in full and be paid in cash no later than the 30th day following the date of the change of control; provided, that the participant has been in continuous employment through the termination or change in control date, as applicable.

On April 20, 2022, the Board of Directors and the Compensation Committee approved the First Amendment to the 2021 Plan, effective as of the same date, which amendment increased the total number of phantom units available for grant
under the 2021 Plan from 2,000,000 units to 5,000,000 units. On April 20, 2022, 365,000 phantom units and 1,097,500 phantom unit appreciation rights were granted to employees of the general partner and its affiliates who perform services for the Partnership. On July 19, 2023, 1,179,500 phantom units and 505,500 phantom unit appreciation rights were granted to employees of the general partner and its affiliates who perform services for the Partnership.

2025 Phantom Unit Plan

On February 11, 2025, the Board of Directors and the Compensation Committee approved the Martin Midstream Partners L.P. 2025 Phantom Unit Plan (the “2025 Plan”) to supersede the 2021 Plan, effective as of the same date. The 2025 Plan contains substantially the same terms and conditions as the 2021 Plan. On February 11, 2025, 1,210,000 phantom units and 425,000 phantom unit appreciation rights were granted to employees of the general partner and its affiliates who perform services for the Partnership. On July 16, 2025, 1,275,000 phantom units and 420,000 phantom unit appreciation rights were granted to employees of the general partner and its affiliates who perform services for the Partnership. See “Item 11. Executive Compensation – Martin Midstream Partners L.P. Long-Term Incentive Plans – Phantom Unit Plan.”

Phantom unit awards are recorded in operating expense and selling, general and administrative expense based on the fair value of the vested portion of the awards on the balance sheet date. The fair value of these awards is updated at each balance sheet date and changes in the fair value of the vested portions of the awards are recorded as increases or decreases to compensation expense within operating expense and selling, general and administrative expense in the Consolidated Statements of Operations. All of the Partnership's outstanding phantom unit awards at December 31, 2025 met the criteria to be treated under liability classification in accordance with ASC 718, given that these awards will settle in cash on the vesting date.

Compensation expense for the phantom awards is based on the fair value of the units as of the balance sheet date as further discussed below, and such costs are recognized ratably over the service period of the awards. As the fair value of liability awards is required to be re-measured each period end, stock compensation expense amounts recognized in future periods for these awards will vary. The estimated future cash payments of these awards are presented as liabilities within "Trade and other accounts payable" and "Other long-term obligations" in the Consolidated Balance Sheets. At December 31, 2025, the total liability recognized in connection with outstanding phantom unit awards was $4,574, of which $2,905 is recorded in "Trade and other accounts payable" and $1,669 is recorded in "Other long-term obligation"s on the Consolidated Balance Sheets. At December 31, 2024, the total liability recognized in connection with outstanding phantom unit awards was $3,480, of which $1,073 is recorded in "Trade and other accounts payable" and $2,407 is recorded in "Other long-term obligations" on the Consolidated Balance Sheets. As of December 31, 2025, there was a total of $5,598 of unrecognized compensation costs related to non-vested phantom unit awards. These costs are expected to be recognized over a remaining life of 1.95 years.

The fair value of the phantom unit awards was estimated using a Monte Carlo valuation model as of the balance sheet date. The Monte Carlo valuation model is based on random projections of stock price paths and must be repeated numerous times to achieve a probabilistic assessment. Expected volatility was calculated based on the historical volatility of the Partnership’s common units as well as a set of peer companies.

Restricted Unit Plan
    On May 26, 2017, the unitholders of the Partnership approved the Martin Midstream Partners L.P. 2017 Restricted Unit Plan (the “2017 LTIP”). The 2017 LTIP currently permits the grant of awards covering an aggregate of 3,000,000 common units, all of which can be awarded in the form of restricted units. The 2017 LTIP is administered by the Compensation Committee.
A restricted unit is a unit that is granted to grantees with certain vesting restrictions, which may be time-based and/or performance-based. Once these restrictions lapse, the grantee is entitled to full ownership of the unit without restrictions. The Compensation Committee may determine to make grants under the 2017 LTIP containing such terms as the Compensation Committee shall determine under the 2017 LTIP. With respect to time-based restricted units ("TBRUs"), the Compensation Committee will determine the time period over which restricted units granted to employees and directors will vest. The Compensation Committee may also award a percentage of restricted units with vesting requirements based upon the achievement of specified pre-established performance targets ("PBRUs"). The performance targets may include, but are not limited to, the following: revenue and income measures, cash flow measures, net income before interest expense and income tax expense ("EBIT"), net income before interest expense, income tax expense, and depreciation and amortization ("EBITDA"), distribution coverage metrics, expense measures, liquidity measures, market measures, corporate sustainability metrics, and
other measures related to acquisitions, dispositions, operational objectives and succession planning objectives. PBRUs are earned only upon our achievement of an objective performance measure for the performance period. PBRUs which vest are payable in common units. Unvested units granted under the 2017 LTIP may or may not participate in cash distributions depending on the terms of each individual award agreement.

The restricted units issued to directors generally vest in equal annual installments over a four-year period.

In February 2025, the Partnership issued 18,000 TBRUs to each of the Partnership's three independent directors under the 2017 LTIP. These restricted common units vest in equal installments of 4,500 units on January 24, 2026, 2027, 2028, and 2029.

     The restricted units are valued at their fair value at the date of grant, which is equal to the market value of common units on such date. A summary of the restricted unit activity for the year ended December 31, 2025 is provided below:
Number of UnitsWeighted Average Grant-Date Fair Value Per Unit
Non-vested, beginning of year168,864 $2.65 
   Granted (TBRU)54,000 $3.62 
   Vested(60,126)$2.75 
   Forfeited— $— 
Non-Vested, end of year162,738 $2.93 
Aggregate intrinsic value, end of year$425 
    A summary of the restricted units’ aggregate intrinsic value (market value at vesting date) and fair value of units vested (market value at date of grant) during the years ended December 31, 2025, 2024 and 2023 is provided below:
For the Year Ended
December 31,
202520242023
Aggregate intrinsic value of units vested$55 $46 $89 
Fair value of units vested$165 $168 $178 

    As of December 31, 2025, there was $301 of unrecognized compensation cost related to non-vested time-based restricted units. That cost is expected to be recognized over a weighted-average period of 2.38 years.
v3.25.4
Income Taxes
 12 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Income Taxes INCOME TAXES
    The components of pretax income (loss) and income tax expense (benefit) from operations for the years ended December 31, 2025, 2024 and 2023 are as follows:
202520242023
Income (loss) from continuing operations before income tax expense (benefit)
US$(9,973)$(1,010)$1,369 
Total$(9,973)-9973$(1,010)$1,369 
Income tax expense (benefit) from continuing operations
Current tax expense (benefit)
US federal$2,174 $2,318 $904 
US state and local1,678 1,625 828 
Total current tax expense (benefit)3,852 3,943 1,732 
Deferred tax expense (benefit)
US federal708 595 3,051 
US state and local212 (341)1,135 
Total deferred tax expense (benefit)920 254 4,186 
Total income tax expense (benefit)
US federal2,882 2,913 3,955 
US state and local1,890 1,284 1,963 
Total income tax expense (benefit)$4,772 $4,197 $5,918 

    The operations of a partnership are generally not subject to income taxes, except for Texas margin tax, because its income is taxed directly to its partners. The Texas margin tax is considered a state income tax and is included in income tax expense on the Consolidated Statements of Operations. Since the tax base on the Texas margin tax is derived from an income-based measure, the margin tax is construed as income tax, and therefore, the recognition of deferred taxes applies to the margin tax. The impact on deferred taxes as a result of this provision is immaterial. State income taxes attributable to the Texas margin tax relating to the operation of the Partnership of $1,152, $925 and $440 were recorded in income tax expense for the years ended December 31, 2025, 2024 and 2023, respectively.

Total income tax expense relating to the operation of MTI, a wholly owned C-Corporation subsidiary of the Partnership (“Taxable Subsidiary”), of $3,620, $3,272 and $5,478 was recorded in income tax expense for the years ended December 31, 2025, 2024 and 2023, respectively.

The income tax expense from the Taxable Subsidiary operations for the years ended December 31, 2025, 2024, and 2023 differs from the "expected" tax expense (computed by applying the federal corporate rate of 21% to income before income taxes of the Taxable Subsidiary) as follows:
202520242023
AmountPercentAmountPercentAmountPercent
US federal statutory income tax rate$2,175 21.00 %$2,669 21.00 %$3,880 21.00 %
Domestic federal reconciling items
Nontaxable and nondeductible items, net:
• Insurance premiums paid to non-insurance company
875 8.45 %265 2.08 %280 1.52 %
• Other
36 0.35 %34 0.27 %26 0.15 %
 Return to provision true-up(64)(0.62)%(45)(0.36)%45 0.24 %
 Other domestic federal items16 0.15 %65 0.51 %44 0.24 %
Domestic state and local income taxes, net of federal effect**582 5.62 %284 2.23 %1,203 6.52 %
Effect of changes in tax laws or rates— — %— — %— — %
Total$3,620 34.95 %$3,272 25.73 %$5,478 29.67 %
**State taxes in Texas made up the majority (greater than 50 percent) of the tax effect in this category

Income taxes paid (net of refunds received) for the years ended December 31, 2025, 2024 and 2023, are as follows:

202520242023
US federal$1,950 $2,340 $560 
Domestic state and local
Florida
*
63 61 
Louisiana
*
56 64 
Tennessee
*
*
59 
Texas1,349 766 510 
Other223 131 150 
Subtotal1,572 1,016 844 
Total$3,522 $3,356 $1,404 
*Jurisdiction is below the five percent disaggregation threshold for the period presented

Deferred taxes are the result of differences between the bases of assets and liabilities for financial reporting and income tax purposes. Significant components of deferred tax assets and liabilities at December 31, 2025 and 2024 are as follows:
20252024
Deferred tax assets:
Bad debt reserves$95 $130 
Goodwill and intangibles8,186 9,216 
Employee benefits10 12 
Operating leases54 30 
Interest expense1,426 1,186 
Tax loss carryforwards40 118 
Other185 150 
Subtotal9,996 10,842 
Less: Valuation allowance— — 
Total net deferred tax assets9,996 10,842 
Deferred tax liabilities:
Property and equipment(970)(896)
Operating leases— — 
Total deferred tax liabilities(970)(896)
Net deferred tax assets$9,026 $9,946 

Deferred tax assets are regularly reviewed for recoverability and a valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The ultimate realization of deferred tax assets is dependent upon future taxable income during the periods in which those temporary differences become deductible. In assessing the need for a valuation allowance, management considers all available positive and negative evidence, including the ability to carryback operating losses to prior periods and the expected future utilization of net operating loss carryforwards, the reversal of deferred tax liabilities, projected taxable income, and tax-planning strategies. On the basis of these considerations, as of December 31, 2025, management believes it is more likely than not that the Taxable Subsidiary will realize the benefit of the existing deferred tax assets.

    Federal income taxes refundable related to the operation of the Taxable Subsidiary of $44 for the year ended December 31, 2024 are included in "Other current assets". "Income taxes payable" includes a state income tax liability related to the operation of the Partnership of $1,136 and $931 for the years ended December 31, 2025 and 2024, respectively. Also included in "Income taxes payable" is a federal income tax liability related to the operation of the Taxable Subsidiary of $182 for the year ended December 31, 2025 and state income tax liabilities related to the operation of the Taxable Subsidiary of $262 and $352 for the years ended December 31, 2025 and 2024, respectively.

    At December 31, 2025, MTI had net operating loss carryforwards for income tax purposes of approximately $859 related to state taxes. Of these net operating loss carryforwards, approximately $854 will expire between 2031 and 2041 and approximately $5 may be carried forward indefinitely. The federal net operating loss carryforwards were fully utilized in 2024.
    
    The operations of the Partnership are generally not subject to income taxes, except as discussed above, because its income is taxed directly to its partners. The net tax basis in the Partnership's assets and liabilities is greater (less) than the reported amounts on the financial statements by approximately $63,929 and $69,103 as of December 31, 2025 and 2024, respectively.

On July 4, 2025, OBBBA was enacted, which legislation included numerous revisions to U.S. federal tax law. The OBBBA legislation does not have a material impact on the Partnership’s financials.

    As of December 31, 2025, the tax years that remain open to assessment are 2022, 2023 and 2024.
v3.25.4
Business Segments
 12 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
Business Segments BUSINESS SEGMENTS
The Chief Operating Decision Maker ("CODM") is a group of executives, comprised of the Chief Executive Officer, Chief Financial Officer and Chief Operating Officer of the Partnership's general partner. CODM may use different operating measures to assess operating results and allocate resources among the Partnership's four segments (outlined below), however
the measure that is most consistent with the amounts included in the consolidated financial statements is operating income. The CODM utilizes this measure to evaluate the current financial performance and project the future financial performance of each segment to determine the allocation of capital resources.

The Partnership's four reportable segments are comprised of (1) Terminalling and Storage, (2) Transportation, (3) Sulfur Services and (4) Specialty Products. The operating segments within each of our reportable segments have been aggregated based on the similarity of their economic and other characteristics, including different product type and services.

The Terminalling and Storage segment generates revenue by providing terminalling, processing, and storage services for petroleum products and by-products. Storage revenue is earned through contracted monthly tank fixed fees, while throughput revenue is based on the volume moved through the Partnership’s terminals at contracted rates. Tolling revenue is derived from contracted monthly reservation fees and throughput volumes processed at the facility.

The Transportation segment earns revenue by offering land and marine transportation services for petroleum products, by-products, chemicals, and specialty products. Land transportation revenue is based on mileage rates for line hauls or completion of contracted trips. Marine transportation revenue comes from time charters, calculated on a per-day basis, or from the completion of contracted trips.

The Sulfur Services segment generates revenue by providing processing, manufacturing, marketing, and distribution services for sulfur and sulfur-based products. Revenue from sulfur and fertilizer product sales is recognized when the customer takes title to the product. Revenue from sulfur services is earned as services are performed during each monthly period.

The Specialty Products segment earns revenue by providing marketing, distribution, and transportation services for NGLs as well as blending and packaging services for specialty lubricants and greases. NGL revenue is recognized upon the sale of products via truck, rail, or pipeline. For lubricants and greases, revenue is recognized upon their sale by truck or rail.
The following tables present selected financial information with respect to the Partnership's operating segments for the years ended December 31, 2025, 2024 and 2023.
Terminalling and StorageTransportationSulfur ServicesSpecialty ProductsIndirect selling, general and administrativeTotal
Year Ended December 31, 2025:
Operating revenues from external customers$90,831 $212,509 $164,079 $248,694 $— $716,113 
Intersegment operating revenues 7,456 16,500 — 109 — 24,065 
Total segment revenues98,287 229,009 164,079 248,803 — 740,178 
Reconciliation of revenues:
Elimination of intersegment revenues(7,456)(16,500)— (109)— (24,065)
Total consolidated revenues90,831 212,509 164,079 248,694 — 716,113 
Less: cost of products sold:
Direct product costs— — 87,008 207,556 — 294,564 
Manufacturing costs (plant, labor, transportation, and other)— — 26,758 18,180 — 44,938 
Segment gross margin98,287 229,009 50,313 23,067 — 400,676 
Less:
Employment related expenses2
26,696 60,987 8,636 5,787 12,274 114,380 
Driver pay — 47,071 — — — 47,071 
Pass-through expenses— 23,676 3,199 — — 26,875 
Utilities, materials, and supplies14,352 2,477 965 118 — 17,912 
Repairs and maintenance4,282 17,633 714 15 — 22,644 
Insurance related expenses4,803 17,167 729 168 116 22,983 
Lease expenses4,481 20,737 465 98 — 25,781 
Other segment expenses1
7,807 8,509 5,577 487 3,595 25,975 
Depreciation and amortization21,209 11,768 14,197 3,023 — 50,197 
(Gain) loss on sale or disposition of property, plant and equipment67 (2,057)(15)(34)— (2,039)
83,697 207,968 34,467 9,662 15,985 351,779 
Operating income (loss)$14,590 $21,041 $15,846 $13,405 $(15,985)$48,897 
Segment assets$156,111 $165,129 $132,397 $68,781 $— $522,418 
Capital expenditures and plant turnaround costs$9,833 $8,693 $11,369 $1,726 $— $31,621 
1 Other segment expenses include outside services, property taxes, terminalling fees, regulatory expenses, professional fees, communications expenses, and many other less significant expense categories used in operations.

2 These employment expenses include allocated overhead from Martin Resource Management Corporation and exclude those that are part of our manufacturing operations. Payroll expenses in our manufacturing operations are included in cost of products sold.
Terminalling and StorageTransportationSulfur ServicesSpecialty ProductsIndirect selling, general and administrativeTotal
Year Ended December 31, 2024:
Operating revenues from external customers$89,067 $223,934 $129,771 $264,850 $— $707,622 
Intersegment operating revenues 7,488 15,873 1 95 — 23,457 
Total segment revenues96,555 239,807 129,772 264,945 — 731,079 
Reconciliation of revenues:
Elimination of intersegment revenues(7,488)(15,873)(1)(95)— (23,457)
Total consolidated revenues89,067 223,934 129,771 264,850 — 707,622 
— 
Less: cost of products sold:
Direct product costs— — 58,102 217,866 — 275,968 
Manufacturing costs (plant, labor, transportation, and other)72 — 21,882 19,536 — 41,490 
Segment gross margin96,483 239,807 49,788 27,543 — 413,621 
Less:
Employment related expenses2
25,714 60,882 9,148 5,941 12,267 113,952 
Driver pay — 50,573 — — — 50,573 
Pass-through expenses— 24,454 2,925 — — 27,379 
Utilities, materials, and supplies13,591 2,254 794 137 — 16,776 
Repairs and maintenance5,776 18,219 706 15 — 24,716 
Insurance related expenses6,914 15,083 730 125 825 23,677 
Lease expenses4,268 16,548 414 121 — 21,351 
Other segment expenses1
7,470 9,296 4,473 996 6,464 28,699 
Depreciation and amortization22,757 13,027 11,769 3,234 — 50,787 
(Gain) loss on sale or disposition of property, plant and equipment(1,105)(713)298 (64)— (1,584)
85,385 209,623 31,257 10,505 19,556 356,326 
Operating income (loss)$11,098 $30,184 $18,531 $17,038 $(19,556)$57,295 
Segment assets$180,769 $165,093 $126,074 $66,573 $— $538,509 
Capital expenditures and plant turnaround costs$13,764 $9,188 $26,380 $3,291 $— $52,623 
1 Other segment expenses include outside services, property taxes, terminalling fees, regulatory expenses, professional fees, communications expenses, and many other less significant expense categories used in operations. The Unallocated SG&A amount includes $3,674 in transaction expenses associated with the terminated merger with Martin Resource Management Corporation.

2 These employment expenses include allocated overhead from Martin Resource Management Corporation and exclude those that are part of our manufacturing operations. Payroll expenses in our manufacturing operations are included in cost of products sold.
Terminalling and StorageTransportationSulfur ServicesSpecialty ProductsIndirect selling, general and administrativeTotal
Year Ended December 31, 2023:
Operating revenues from external customers$86,514 $223,677 $140,995 $346,777 $— $797,963 
Intersegment operating revenues 8,945 17,249 — 86 — 26,280 
Total segment revenue95,459 240,926 140,995 346,863 — 824,243 
Reconciliation of revenues:
Elimination of intersegment revenues(8,945)(17,249)— (86)— (26,280)
Total consolidated revenues86,514 223,677 140,995 346,777 — 797,963 
— 
Less: cost of products sold:
Direct product costs— — 75,002 294,005 — 369,007 
Manufacturing costs (plant, labor, transportation, and other)75 — 18,839 25,195 — 44,109 
Segment gross margin95,384 240,926 47,154 27,663 — 411,127 
Less:
Employment related expenses2
23,018 56,244 7,997 5,463 12,755 105,477 
Driver pay — 52,650 — — 52,650 
Pass-through expenses— 27,196 3,657 — 30,853 
Utilities, materials, and supplies16,863 2,134 1,225 157 20,379 
Repairs and maintenance4,259 22,582 340 45 27,226 
Insurance related expenses4,525 14,056 759 122 19,462 
Lease expenses3,779 11,544 375 135 15,833 
Other segment expenses1
7,019 7,715 4,716 1,276 3,275 24,001 
Depreciation and amortization21,030 14,879 10,690 3,296 — 49,895 
(Gain) loss on sale of property, plant and equipment359 (1,775)(17)60 — (1,373)
80,852 207,225 29,742 10,554 16,030 344,403 
Operating income (loss)$14,532 $33,701 $17,412 $17,109 $(16,030)$66,724 
Segment assets$171,320 $161,506 $103,779 $72,770 $— $509,375 
Capital expenditures and plant turnaround costs$13,168 $7,598 $16,851 $2,519 $— $40,136 
1 Other segment expenses include outside services, property taxes, terminalling fees, regulatory expenses, professional fees, communications expenses, and many other less significant expense categories used in operations.

2 These employment expenses include allocated overhead from Martin Resource Management Corporation and exclude those that are part of our manufacturing operations. Payroll expenses in our manufacturing operations are included in cost of products sold.
Revenues from one customer in the specialty products segment was $118,207, $122,105 and $120,171 for the years ended December 31, 2025, 2024 and 2023, respectively.
v3.25.4
Commitments and Contingencies
 12 Months Ended
Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies COMMITMENTS AND CONTINGENCIES
Contingencies

From time to time, the Partnership is subject to various claims and legal actions arising in the ordinary course of business. In the opinion of management, the ultimate disposition of these matters will not have a material adverse effect on the Partnership.
    
On December 31, 2015, the Partnership received a demand from a customer in its lubricants packaging business for defense and indemnity in connection with various lawsuits filed against it, which generally alleged that the customer engaged in unlawful and deceptive business practices in connection with its marketing and advertising of its private label motor oil (the “Marketing Lawsuits”). The Partnership disputed and continues to dispute that it has any obligation to defend or indemnify the customer for the customer’s conduct. Accordingly, on January 7, 2016, the Partnership filed a Complaint for Declaratory Judgment in the Chancery Court of Davidson County, Tennessee (the “Tennessee Court”), under Case No. 16-0018-BC, requesting a judicial determination that the Partnership did not owe the customer the demanded defense and indemnity obligations (the “Litigation”). The Marketing Lawsuits pending in federal court against the customer were transferred to the U.S. District Court for the Western District of Missouri under the consolidated case MDL No. 2709 for pretrial proceedings (the “Consolidated Lawsuits”). On March 1, 2017, at the joint request of the customer and the Partnership, the Tennessee Court administratively closed the Litigation. In 2021, the customer settled the Consolidated Lawsuits. On December 17, 2021, at the request of the customer, the Tennessee Court reopened the Litigation and the customer asserted various counterclaims against the Partnership seeking, among other things, to recover its costs of defending and settling the Consolidated Lawsuits. At this time, we are unable to determine what ultimate exposure we may have in this matter, if any. The Partnership intends to vigorously defend the counterclaims asserted by the customer in the Litigation. The trial for the Litigation is expected to be held in 2026.
v3.25.4
Investment in DSM Semichem LLC
 12 Months Ended
Dec. 31, 2025
Schedule of Investments [Abstract]  
Investment in DSM Semichem LLC INVESTMENT IN DSM SEMICHEM LLC
On October 19, 2022, Martin ELSA Investment LLC, the Partnership's affiliate, entered into definitive agreements with Samsung C&T America, Inc. and Dongjin USA, Inc., an affiliate of Dongjin Semichem Co., Ltd., to form DSM Semichem LLC (“DSM”). DSM will produce and distribute electronic level sulfuric acid (“ELSA”). By leveraging the Partnership's existing assets located in Plainview, Texas and installing additional facilities (the “ELSA Facility”) as required, DSM will produce ELSA that meets the strict quality standards required by the recent advances in semiconductor manufacturing. In addition to owning a 10% non-controlling interest in DSM, the Partnership will be the exclusive provider of feedstock to the ELSA Facility. The Partnership, through its affiliate MTI, will also provide land transportation services for the ELSA produced by DSM. On April 1, 2024, the Partnership contributed $6,500 in cash to DSM, which represents the cash contribution required pursuant to DSM's limited liability agreement for the Partnership's 10% non-controlling interest. Also, in conjunction with the formation of DSM, we contributed approximately 22 acres of land. The Partnership recognizes its 10% interest in DSM as "Investment in DSM Semichem LLC" on its Consolidated Balance Sheets. The Partnership accounts for its ownership interest in DSM under the equity method of accounting.

Selected financial information for DSM is as follows:
As of December 31,Year ended December 31,
Total AssetsLong-Term DebtMembers' Equity/Partners' CapitalRevenuesNet Income (Loss)
2025
DSM Semichem LLC$113,007 $25,521 $57,598 $—$(10,916)
2024
DSM Semichem LLC$105,773 $31,700 $68,513 $—$(6,240)
v3.25.4
Condensed Consolidating Financial Information
 12 Months Ended
Dec. 31, 2025
Consolidating Financial Statements [Abstract]  
Condensed Consolidating Financial Information CONDENSED CONSOLIDATING FINANCIAL INFORMATION    The Partnership's operations are conducted by its operating subsidiaries as it has no independent assets or operations. The Operating Partnership, the Partnership’s wholly owned subsidiary, and the Partnership's other operating subsidiaries have issued in the past, and may issue in the future, unconditional guarantees of senior or subordinated debt securities of the Partnership. The guarantees that have been issued are full, irrevocable and unconditional and joint and several. In addition, the Operating Partnership may also issue senior or subordinated debt securities which, if issued, will be fully, irrevocably and unconditionally guaranteed by the Partnership. Substantially all of the Partnership's operating subsidiaries are subsidiary guarantors of its outstanding 2028 Notes and any subsidiaries other than the subsidiary guarantors are minor.
v3.25.4
Subsequent Events
 12 Months Ended
Dec. 31, 2025
Subsequent Events [Abstract]  
Subsequent Events SUBSEQUENT EVENTSQuarterly Distribution.  On January 22, 2026, the Partnership declared a quarterly cash distribution of $0.005 per common unit for the fourth quarter of 2025, or $0.02 per common unit on an annualized basis, which was paid on February 13, 2026 to unitholders of record as of February 6, 2026.
v3.25.4
Insider Trading Arrangements
 3 Months Ended
Dec. 31, 2025
Trading Arrangements, by Individual  
Rule 10b5-1 Arrangement Adopted false
Non-Rule 10b5-1 Arrangement Adopted false
Rule 10b5-1 Arrangement Terminated false
Non-Rule 10b5-1 Arrangement Terminated false
v3.25.4
Insider Trading Policies and Procedures
 12 Months Ended
Dec. 31, 2025
Insider Trading Policies and Procedures [Line Items]  
Insider Trading Policies and Procedures Adopted true
v3.25.4
Cybersecurity Risk Management and Strategy Disclosure
 12 Months Ended
Dec. 31, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]  
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]
The Partnership recognizes the critical importance of developing, implementing, and maintaining robust cybersecurity measures to safeguard our information systems and protect the confidentiality, integrity, and availability of our data.

Managing Material Risks & Integrated Overall Risk Management

The Partnership has strategically integrated cybersecurity risk management into our broader risk management framework to promote an entity-wide culture of cybersecurity risk management. Our information technology department works closely with our internal audit, risk, and legal teams to continuously evaluate and address cybersecurity risks and ensure cybersecurity measures are in alignment with our business objectives and operational needs.

Our cybersecurity measures are designed to identify, protect, detect, and respond to and manage reasonably foreseeable cybersecurity risks and threats. To protect our information systems from cybersecurity threats, we use multiple monitoring and detection tools to safeguard network and endpoint devices. We have implemented measures that proactively and continuously assess and monitor our information systems for vulnerabilities and cybersecurity exposure.

Engage Third Parties on Risk Management

Recognizing the complexity and evolving nature of cybersecurity threats, the Partnership engages with a range of external experts, including cybersecurity consultants in evaluating and testing our risk management systems. Our collaboration with these third parties includes regular audits, network penetration testing, threat assessments, and consultation on security enhancements.

We provide awareness training to our employees to help identify, avoid, and mitigate cybersecurity threats. Our employees with network access are required to complete annual security awareness training and quarterly spear phishing exercises.

Oversee Third-Party Risk

Because we are aware of the risks associated with third-party vendors, service providers and business partners, we have implemented stringent processes to oversee and manage these risks. We conduct thorough and annual security assessments of all third-party file transfer protocols, and we perform in-depth reviews of hosted applications including, but not limited to, confirmation of SOC 2, ISO 27001, or other relevant security certifications.

Risks from Cybersecurity Threats

We have not been subject to cybersecurity challenges that have materially impaired or are reasonably likely to materially impair our operations or financial standing.
Cybersecurity Risk Management Processes Integrated [Flag] true
Cybersecurity Risk Management Processes Integrated [Text Block] The Partnership has strategically integrated cybersecurity risk management into our broader risk management framework to promote an entity-wide culture of cybersecurity risk management
Cybersecurity Risk Management Third Party Engaged [Flag] true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag] true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag] false
Cybersecurity Risk Board of Directors Oversight [Text Block]
The Board of Directors is acutely aware of the critical nature of managing risks associated with cybersecurity threats. The Board of Directors has established robust oversight mechanisms and is willing to cause the Partnership to expend significant resources to further enhance digital security or to remediate vulnerabilities to ensure effective governance in managing risks associated with cybersecurity threats. The Board of Directors recognizes the significance of these cybersecurity threats to our operational integrity and stakeholder confidence.

Board of Directors Oversight

The Board of Directors has oversight of cybersecurity risks and is composed of board members with diverse expertise including, risk management, technology, and finance, equipping them to oversee cybersecurity risks effectively.
Management’s Role Managing Risk

The Director of Internal Audit and the Chief Financial Officer (“CFO”) play a pivotal role in informing the Board of Directors on cybersecurity risks. They provide comprehensive briefings to the Board of Directors on a regular basis, with a minimum frequency of once per year. These briefings encompass a broad range of topics, including:

•Current cybersecurity landscape and emerging threats;
•Status of ongoing cybersecurity initiatives and strategies;
•Incident reports and learnings from any cybersecurity events; and
•Compliance with regulatory requirements and industry standards.

In addition to our scheduled meetings, the Board of Directors, Director of Internal Audit, Director of Information Technology and CFO maintain an ongoing dialogue regarding emerging or potential cybersecurity risks. Together, they receive updates on significant developments in the cybersecurity domain, ensuring the Board of Directors' oversight is proactive and responsive. The Board of Directors actively participates in strategic decisions related to cybersecurity, offering guidance and approval for major initiatives. This involvement ensures that cybersecurity considerations are integrated into the broader strategic objectives of the Partnership. The Board of Directors conducts an annual review of the Partnership’s cybersecurity posture and the effectiveness of its risk management strategies. This review helps in identifying areas for improvement and ensuring the alignment of cybersecurity efforts with the overall risk management framework.

Reporting to the Board of Directors

The Directors of Information Technology and Internal Audit regularly inform executive management of all aspects related to cybersecurity risks and incidents. This ensures that the highest levels of management are kept abreast of the cybersecurity posture and potential risks facing the Partnership. Furthermore, significant cybersecurity matters, and strategic risk management decisions are escalated to the Board of Directors, ensuring that they have comprehensive oversight and can provide guidance on critical cybersecurity issues.

Monitor Cybersecurity Incidents

The Director of Information Technology is continually informed about the latest developments in cybersecurity, including potential threats and innovative risk management techniques. The Director of Information Technology implements and oversees processes for the regular monitoring of our information systems. This includes the deployment of advanced security measures and regular system audits to identify potential vulnerabilities. In the event of a cybersecurity incident, the Partnership's information technology team is equipped with an incident response plan. This plan includes immediate actions to mitigate and contain the impact and strategies for remediation and prevention of future incidents.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]
The Board of Directors has oversight of cybersecurity risks and is composed of board members with diverse expertise including, risk management, technology, and finance, equipping them to oversee cybersecurity risks effectively.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block] Together, they receive updates on significant developments in the cybersecurity domain, ensuring the Board of Directors' oversight is proactive and responsive. The Board of Directors actively participates in strategic decisions related to cybersecurity, offering guidance and approval for major initiatives. This involvement ensures that cybersecurity considerations are integrated into the broader strategic objectives of the Partnership. The Board of Directors conducts an annual review of the Partnership’s cybersecurity posture and the effectiveness of its risk management strategies. This review helps in identifying areas for improvement and ensuring the alignment of cybersecurity efforts with the overall risk management framework.
Cybersecurity Risk Role of Management [Text Block]
Management’s Role Managing Risk

The Director of Internal Audit and the Chief Financial Officer (“CFO”) play a pivotal role in informing the Board of Directors on cybersecurity risks. They provide comprehensive briefings to the Board of Directors on a regular basis, with a minimum frequency of once per year. These briefings encompass a broad range of topics, including:

•Current cybersecurity landscape and emerging threats;
•Status of ongoing cybersecurity initiatives and strategies;
•Incident reports and learnings from any cybersecurity events; and
•Compliance with regulatory requirements and industry standards.

In addition to our scheduled meetings, the Board of Directors, Director of Internal Audit, Director of Information Technology and CFO maintain an ongoing dialogue regarding emerging or potential cybersecurity risks. Together, they receive updates on significant developments in the cybersecurity domain, ensuring the Board of Directors' oversight is proactive and responsive. The Board of Directors actively participates in strategic decisions related to cybersecurity, offering guidance and approval for major initiatives. This involvement ensures that cybersecurity considerations are integrated into the broader strategic objectives of the Partnership. The Board of Directors conducts an annual review of the Partnership’s cybersecurity posture and the effectiveness of its risk management strategies. This review helps in identifying areas for improvement and ensuring the alignment of cybersecurity efforts with the overall risk management framework.

Reporting to the Board of Directors

The Directors of Information Technology and Internal Audit regularly inform executive management of all aspects related to cybersecurity risks and incidents. This ensures that the highest levels of management are kept abreast of the cybersecurity posture and potential risks facing the Partnership. Furthermore, significant cybersecurity matters, and strategic risk management decisions are escalated to the Board of Directors, ensuring that they have comprehensive oversight and can provide guidance on critical cybersecurity issues.

Monitor Cybersecurity Incidents

The Director of Information Technology is continually informed about the latest developments in cybersecurity, including potential threats and innovative risk management techniques. The Director of Information Technology implements and oversees processes for the regular monitoring of our information systems. This includes the deployment of advanced security measures and regular system audits to identify potential vulnerabilities. In the event of a cybersecurity incident, the Partnership's information technology team is equipped with an incident response plan. This plan includes immediate actions to mitigate and contain the impact and strategies for remediation and prevention of future incidents.
Cybersecurity Risk Management Positions or Committees Responsible [Flag] true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]
In addition to our scheduled meetings, the Board of Directors, Director of Internal Audit, Director of Information Technology and CFO maintain an ongoing dialogue regarding emerging or potential cybersecurity risks. Together, they receive updates on significant developments in the cybersecurity domain, ensuring the Board of Directors' oversight is proactive and responsive. The Board of Directors actively participates in strategic decisions related to cybersecurity, offering guidance and approval for major initiatives. This involvement ensures that cybersecurity considerations are integrated into the broader strategic objectives of the Partnership. The Board of Directors conducts an annual review of the Partnership’s cybersecurity posture and the effectiveness of its risk management strategies. This review helps in identifying areas for improvement and ensuring the alignment of cybersecurity efforts with the overall risk management framework.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]
The Board of Directors has oversight of cybersecurity risks and is composed of board members with diverse expertise including, risk management, technology, and finance, equipping them to oversee cybersecurity risks effectively.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block] The Directors of Information Technology and Internal Audit regularly inform executive management of all aspects related to cybersecurity risks and incidents. This ensures that the highest levels of management are kept abreast of the cybersecurity posture and potential risks facing the Partnership. Furthermore, significant cybersecurity matters, and strategic risk management decisions are escalated to the Board of Directors, ensuring that they have comprehensive oversight and can provide guidance on critical cybersecurity issues.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag] true
v3.25.4
Significant Accounting Policies and Practices (Policies)
 12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Principles of Presentation and Consolidation Principles of Presentation and Consolidation
    The consolidated financial statements include the financial statements of the Partnership and its wholly owned subsidiaries and equity method investees. In the opinion of the management of the Partnership’s general partner, all adjustments and elimination of significant intercompany balances necessary for a fair presentation of the Partnership’s results of operations, financial position and cash flows for the periods shown have been made. All such adjustments are of a normal recurring nature. In addition, the Partnership evaluates its relationships with other entities to identify whether they are variable interest entities under certain provisions of the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC"), 810-10 and to assess whether it is the primary beneficiary of such entities. If the determination is made that the Partnership is the primary beneficiary, then that entity is included in the consolidated financial statements in accordance with ASC 810-10. No such variable interest entities existed as of December 31, 2025 or 2024.
Product Exchanges Product Exchanges
 
The Partnership enters into product exchange agreements with third parties, whereby the Partnership agrees to exchange NGLs and sulfur with third parties. The Partnership records the balance of exchange products due to other companies under these agreements at quoted market product prices and the balance of exchange products due from other companies at the lower of cost or market. Cost is determined using the first-in, first-out ("FIFO") method. Product exchanges with the same counterparty are entered into in contemplation of one another and are combined. The net amount related to location differentials is reported in "Product sales" or "Cost of products sold" in the Consolidated Statements of Operations.
Inventories Inventories
 
Inventories are stated at the lower of cost or net realizable value. NGLs, sulfur, and all other inventories not otherwise specified are accounted for using the FIFO method. Lubricants, greases, and lubricant packaging inventories are accounted for using standard cost, which approximates actual cost. Fertilizer inventories are accounted for using weighted average cost, which approximates actual cost.
Revenue Recognition Revenue Recognition
 
Terminalling and Storage – Revenue is recognized for storage contracts based on the contracted monthly tank fixed fee. For throughput contracts, revenue is recognized based on the volume moved through the Partnership’s terminals at the contracted rate. For storage and throughput contracts at the Partnership's underground NGL storage facility, revenue is recognized based on the volume stored and moved through the facility at the contracted rate. For the Partnership’s tolling agreement, revenue is recognized based on the contracted monthly reservation fee and throughput volumes moved through the facility.  

Transportation – Revenue related to land transportation is recognized for line hauls based on a mileage rate. For contracted trips, revenue is recognized upon completion of the particular trip. The performance of the service is invoiced as the transaction occurs and is generally paid within a month. Revenue related to marine transportation is recognized for time charters based on a per day rate. For contracted trips, revenue is recognized upon completion of the particular trip. The performance of the service is invoiced as the transaction occurs and is generally paid within a month.

Sulfur Services – Revenue from sulfur and fertilizer product sales is recognized when the customer takes title to the product. Delivery of the product is invoiced as the transaction occurs and is generally paid within a month. Revenue from sulfur services is recognized as services are performed during each monthly period. The performance of the service is invoiced as the transaction occurs and is generally paid within a month.
Specialty Products – NGL revenue is recognized when title is transferred, which is generally when the product is delivered by truck, rail, or pipeline to the Partnership's NGL customers or when the customer picks up the product from our facilities. When lubricants are sold by truck or rail, revenue is recognized when title is transferred, which is generally when the product leaves the Partnership's facility, but can vary based on the specific terms of the contract. The product is invoiced as the transaction occurs and is generally paid within a month.
Equity Method Investments Equity Method Investments
 
The Partnership uses the equity method of accounting for investments in unconsolidated entities where the ability to exercise significant influence over such entities exists. Investments in unconsolidated entities consist of capital contributions and advances plus the Partnership’s share of accumulated earnings as of the entities’ latest fiscal year-ends, less capital withdrawals and distributions. Equity method investments are subject to impairment under the provisions of ASC 323-10, which relates to the equity method of accounting for investments in common stock. No portion of the net income from these entities is included in the Partnership’s operating income.
Property, Plant and Equipment Property, Plant, and Equipment
Owned property, plant, and equipment is stated at cost, less accumulated depreciation. Owned buildings and equipment are depreciated using the straight-line method over the estimated lives of the respective assets.

Equipment under finance leases is stated at the present value of minimum lease payments less accumulated amortization. Equipment under finance leases is amortized on a straight-line basis over the estimated useful life of the asset.

Routine maintenance and repairs are charged to expense while costs of betterments and renewals are capitalized. When an asset is retired or sold, its cost and related accumulated depreciation are removed from the accounts, and the difference between net book value of the asset and proceeds from disposition is recognized as gain or loss.
Goodwill and Other Intangible Assets Goodwill and Other Intangible Assets
Goodwill is subject to a fair-value based impairment test on an annual basis, or more often if events or circumstances indicate there may be impairment. The Partnership is required to identify its reporting units and determine the carrying value of each reporting unit by assigning the assets and liabilities, including the existing goodwill and intangible assets. The Partnership is required to determine the fair value of each reporting unit and compare it to the carrying amount of the reporting unit. To the extent the carrying amount of a reporting unit exceeds the fair value of the reporting unit, the Partnership will record the amount of goodwill impairment as the excess of a reporting unit's carrying amount over its fair value, not to exceed the total amount of goodwill allocated to the reporting unit.
    When assessing the recoverability of goodwill and other intangible assets, the Partnership may first assess qualitative factors in determining whether it is more likely than not that the fair value of a reporting unit or other intangible asset is less than its carrying amount. After assessing qualitative factors, if the Partnership determines that it is not more likely than not that the fair value of a reporting unit or other intangible asset is less than its carrying amount, then performing a quantitative assessment is not required. If an initial qualitative assessment indicates that it is more likely than not the carrying amount exceeds the fair value of a reporting unit or other intangible asset, a quantitative analysis will be performed. The Partnership may also elect to bypass the qualitative assessment and proceed directly to a quantitative analysis depending on the facts and circumstances.

Of the Partnership's four reporting units, the terminalling and storage, transportation, specialty products and sulfur services reporting units all contain goodwill.

    In performing a quantitative analysis, recoverability of goodwill for each reporting unit is measured using a weighting of the discounted cash flow method and two market approaches (the guideline public company method and the guideline transaction method). The discounted cash flow model incorporates discount rates commensurate with the risks involved. Use of a discounted cash flow model is common practice in assessing impairment in the absence of available transactional market evidence to determine the fair value. The key assumptions used in the discounted cash flow valuation model include discount rates, growth rates, cash flow projections and terminal value rates. Discount rates, growth rates and cash flow projections are the most sensitive and susceptible to change as they require significant management judgment. Discount rates are determined by using a weighted average cost of capital ("WACC"). The WACC considers market and industry data as well as company-specific risk factors for each reporting unit in determining the appropriate discount rate to be used. The discount rate utilized for each reporting unit is indicative of the return an investor would expect to receive for investing in such a business. Management, considering industry and company specific historical and projected data, develops growth rates and cash flow projections for each reporting unit. Terminal value rate determination follows common methodology of capturing the present value of perpetual cash flow estimates beyond the last projected period assuming a constant WACC and low long-term growth rates. If the calculated fair value is less than the current carrying amount, the Partnership will record the amount of goodwill impairment as the excess of a reporting unit's carrying amount over its fair value, not to exceed the total amount of goodwill allocated to the reporting unit.

Significant changes in these estimates and assumptions could materially affect the determination of fair value for each reporting unit which could give rise to future impairment. Changes to these estimates and assumptions can include, but may not be limited to, varying commodity prices, volume changes and operating costs due to market conditions and/or alternative providers of services.

Based upon the most recent annual review as of August 31, 2025, no goodwill impairment exists within the Partnership's reporting units for the year ended December 31, 2025. No goodwill impairment was recorded for the years ended December 31, 2024 or 2023.
Other intangible assets that have finite lives are tested for impairment when events or circumstances indicate that the carrying value may not be recoverable. An impairment is indicated if the carrying amount of a long-lived intangible asset exceeds the sum of the undiscounted future cash flows expected to result from the use and eventual disposition of the asset. If impairment is indicated, the Partnership would record an impairment loss equal to the difference between the carrying value and the fair value of the asset.
Debt Issuance Costs Debt Issuance CostsDebt issuance costs relating to the Partnership’s credit facility and senior notes are deferred and amortized over the terms of the debt arrangements and are shown, net of accumulated amortization, as a reduction of the related long-term debt.
Impairment of Long-Lived Assets Impairment of Long-Lived Assets
 
In accordance with ASC 360-10, long-lived assets, such as property, plant and equipment, and intangible assets with definite lives are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be disposed of would be separately presented in the balance sheet and reported at the lower of the carrying amount or fair value less costs to sell and would no longer be depreciated. The assets and liabilities of a disposed group classified as held for sale would be presented separately in the appropriate asset and liability sections of the balance sheet.
Asset Retirement Obligations Asset Retirement Obligations
Under ASC 410-20, which relates to accounting requirements for costs associated with legal obligations to retire tangible, long-lived assets, the Partnership records an asset retirement obligation at present value based upon estimated costs to retire the asset in the period in which it is incurred by increasing the carrying amount of the related long-lived asset. In each subsequent period, the liability is accreted over time towards the ultimate obligation amount and the capitalized costs are depreciated over the useful life of the related asset.
Use of Estimates Use of Estimates
Management has made a number of estimates and assumptions relating to the reporting of assets and liabilities and the disclosure of contingent assets and liabilities to prepare these consolidated financial statements in conformity with accounting principles generally accepted in the U.S. Actual results could differ from those estimates.
Environmental Liabilities and Litigation Environmental Liabilities and Litigation
 
The Partnership’s policy is to accrue for losses associated with environmental remediation obligations when such losses are probable and reasonably estimable. Accruals for estimated losses from environmental remediation obligations generally are recognized no later than completion of the remedial feasibility study. Such accruals are adjusted as further information develops or circumstances change. Costs of future expenditures for environmental remediation obligations are not discounted to their present value. Recoveries of environmental remediation costs from other parties are recorded as assets when their receipt is deemed probable.
Trade and Accrued Accounts Receivable and Allowance for Doubtful Accounts Trade and Accrued Accounts Receivable and Allowance for Doubtful Accounts
 
Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The allowance for doubtful accounts is the Partnership’s best estimate of the amount of probable credit losses in the Partnership’s existing accounts receivable.
Deferred Catalyst Costs Deferred Catalyst Costs
The cost of the periodic replacement of catalysts is deferred and amortized over the catalyst’s estimated useful life, which ranges from 12 to 36 months.
Deferred Turnaround Costs Deferred Turnaround Costs
The Partnership capitalizes the cost of major turnarounds and amortizes these costs over the estimated period to the next turnaround, which ranges from 12 to 36 months.
Income Taxes Income Taxes
 
The Partnership is subject to the Texas margin tax, which is considered a state income tax, and is included in income tax expense on the Consolidated Statements of Operations. Since the tax base on the Texas margin tax is derived from an income-based measure, the margin tax is construed as an income tax and, therefore, the recognition of deferred taxes applies to the margin tax. The impact on deferred taxes as a result of this provision is immaterial.

The Partnership's financial statements recognize the current and deferred income tax consequences that result from the activities of its wholly owned C-Corporation subsidiary, Martin Transport, Inc. ("MTI"), during the current period pursuant to the provisions of the FASB ASC 740 related to income taxes. As a result of the common control transaction with the Partnership, the deferred tax consequences of the changes in the tax bases of MTI’s assets and liabilities were included in equity under the provisions of ASC 740-20-45-11.

With respect to MTI, income taxes are accounted for under the asset and liability method, whereby deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date.

In the ordinary course of business, there may be many transactions and calculations where the ultimate tax outcome is uncertain. The calculation of tax liabilities involves dealing with uncertainties in the application of complex tax laws. In accordance with the provisions of ASC 740, we use a two-step approach for recognizing and measuring tax benefits taken or expected to be taken in a tax return. In the first step, “recognition”, the Partnership determines whether it is more likely than not that a tax position will be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. In evaluating whether a tax position has met the more-likely-than-not recognition threshold, the Partnership presumes that the position will be examined by the appropriate taxing authority that has full knowledge of all relevant information. In the second step, “measurement”, a tax position that meets the more-likely-than-not threshold is measured to determine the amount of benefit to recognize in the financial statements. The tax position is measured at the largest amount of benefit that is greater than 50 percent likely of being realized upon ultimate settlement based upon management’s intent regarding negotiation and litigation. In evaluating all income tax positions for all open years, management has determined all positions are more likely than not to be sustained at full benefit based upon their technical merit under applicable tax laws.
Recent Accounting Pronouncements RECENT ACCOUNTING PRONOUNCEMENTS
In November 2023, the FASB issued ASU 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures" ("ASU 2023-07"). ASU 2023-07 requires annual and interim disclosures that are expected to improve reportable segment disclosures, primarily through enhanced disclosures about significant segment expenses. The provisions of ASU 2023-07 are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The Partnership adopted ASU 2023-07 and its expanded segment disclosure requirements in compliance with the required adoption guidelines.

In December 2023, the FASB issued ASU 2023-09, “Improvements to Income Tax Disclosures” ("ASU 2023-09"), which requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as additional information on income taxes paid. The provisions of ASU 2023-09 are effective for annual reporting periods beginning after December 15, 2024, with early adoption permitted and can be applied on either a prospective or retroactive basis. The Partnership adopted ASU 2023-09 and its expanded disclosure requirements, on a retrospective basis, in compliance with the required adoption guidelines.
Fair Value Measurements The Partnership uses a valuation framework based upon inputs that market participants use in pricing certain assets and liabilities. These inputs are classified into two categories: observable inputs and unobservable inputs. Observable inputs represent market data obtained from independent sources. Unobservable inputs represent the Partnership's own market assumptions. Unobservable inputs are used only if observable inputs are unavailable or not reasonably available without undue cost and effort. The two types of inputs are further prioritized into the following hierarchy:
Level 1: Quoted market prices in active markets for identical assets or liabilities.
Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data.
Level 3: Unobservable inputs that reflect the entity's own assumptions and are not corroborated by market data.
Fair Value of Financial Instruments The Partnership is required to disclose estimated fair values for its financial instruments. Fair value estimates are set forth below for these financial instruments. The following methods and assumptions were used to estimate the fair value of each class of financial instrument:
•Accounts and other receivables, trade and other accounts payable, accrued interest payable, other accrued liabilities, income taxes payable and due from/to affiliates: The carrying amounts approximate fair value due to the short maturity and highly liquid nature of these instruments, and as such these have been excluded from the table below. There is negligible credit risk associated with these instruments.
•Current and non-current portion of long-term debt: The carrying amount of the credit facility approximates fair value due to the debt having a variable interest rate and is in Level 2. The estimated fair value of the 2028 Notes is considered Level 2, as the fair value is based upon quoted prices for identical liabilities in markets that are not active.
v3.25.4
Exit Activities and Divestitures (Tables)
 12 Months Ended
Dec. 31, 2025
Discontinued Operations and Disposal Groups [Abstract]  
Schedule of Revenue and Costs of Disposal Group
202520242023
Products revenue$— $— $70,539 
Cost of products sold— — 72,283 
Selling, general and administrative expenses— — 512 
$— $— $(2,256)
v3.25.4
Revenue (Tables)
 12 Months Ended
Dec. 31, 2025
Revenue from Contract with Customer [Abstract]  
Schedule of Disaggregation of Revenue The following table disaggregates our revenue by major source:
202520242023
Terminalling and storage segment
Throughput and storage$90,831 $89,067 $86,514 
$90,831 $89,067 $86,514 
Transportation segment
Land transportation$156,300 $165,353 $166,717 
Inland transportation46,955 51,826 50,890 
Offshore transportation9,254 6,755 6,070 
$212,509 $223,934 $223,677 
Sulfur service segment
Sulfur product sales$38,380 $31,347 $30,170 
Fertilizer product sales109,258 83,852 97,395 
Sulfur services 16,441 14,572 13,430 
$164,079 $129,771 $140,995 
Specialty products segment
Natural gas liquids product sales$139,940 $144,238 $214,713 
Lubricant product sales108,754 120,612 132,064 
$248,694 $264,850 $346,777 
Total revenues$716,113 $707,622 $797,963 
Schedule of Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
20262027202820292030ThereafterTotal
Terminalling and Storage
Throughput and storage$45,672 $47,042 $48,454 $49,907 $51,404 $52,947 $295,426 
Specialty Products
Natural Gas Liquids3,934 — — — — — 3,934 
Sulfur Services
Product sales14,237 14,237 14,237 — — — 42,711 
Service revenues10,384 7,454 6,953 6,953 2,655 36,506 70,905 
Total$74,227 $68,733 $69,644 $56,860 $54,059 $89,453 $412,976 
v3.25.4
Inventories (Tables)
 12 Months Ended
Dec. 31, 2025
Inventory Disclosure [Abstract]  
Schedule of Components of Inventory
Components of inventories at December 31, 2025 and 2024 were as follows: 
 20252024
Natural Gas Liquids$1,125 $2,814 
Sulfur1,300 1,440 
Fertilizer21,666 18,463 
Lubricants20,281 23,227 
Other5,876 5,763 
 $50,248 $51,707 
v3.25.4
Property, Plant, and Equipment (Tables)
 12 Months Ended
Dec. 31, 2025
Property, Plant and Equipment [Abstract]  
Schedule of Property, Plant and Equipment
At December 31, 2025 and 2024, property, plant and equipment consisted of the following:
 Depreciable Lives20252024
Land—$18,812 $18,812 
Improvements to land and buildings
10-25 years
142,035 136,609 
Storage equipment
5-50 years
131,707 130,663 
Marine vessels
4-25 years
201,831 194,406 
Operating plant and equipment
3-50 years
421,088 396,631 
Furniture, fixtures and other equipment
3-20 years
7,629 7,908 
Transportation equipment
3-7 years
39,115 43,807 
Construction in progress 8,536 25,223 
  $970,753 $954,059 
v3.25.4
Goodwill (Tables)
 12 Months Ended
Dec. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule of Goodwill The following table represents the goodwill balance by reporting unit at December 31, 2025 and 2024 as follows:
20252024
Carrying amount of goodwill:
Terminalling and storage$6,756 $6,756 
Specialty products4,229 4,229 
Sulfur services 5,197 5,197 
Transportation489 489 
        Total goodwill$16,671 $16,671 
v3.25.4
Leases (Tables)
 12 Months Ended
Dec. 31, 2025
Leases [Abstract]  
Schedule of Components of Lease Expense The components of lease expense for the years ended December 31, 2025, 2024, and 2023 were as follows:
202520242023
Operating lease cost$26,747 $22,256 $16,198 
Finance lease cost:
     Amortization of right-of-use assets15 11 6 
     Interest on lease liabilities4 3 — 
Short-term lease cost5,691 4,748 5,415 
Variable lease cost100 163 191 
Total lease cost$32,557 $27,181 $21,810 
    Supplemental cash flow information for the years ended December 31, 2025, 2024, and 2023 related to leases were as follows:
202520242023
Cash paid for amounts included in the measurement of lease liabilities:
     Operating cash flows from operating leases$48,374 $39,763 $29,820 
     Operating cash flows from finance leases4 3 — 
     Financing cash flows from finance leases14 9 9 
Right-of-use assets obtained in exchange for lease obligations:
     Operating leases$23,402 $21,133 $38,935 
     Finance leases— 77 — 
Schedule of Supplemental Balance Sheet Information
Supplemental balance sheet information related to leases was as follows at December 31, 2025 and 2024:
20252024
Operating Leases
Operating lease right-of-use assets$69,938 $67,140 
Current portion of operating lease liabilities included in "Other accrued liabilities"$22,043 $19,707 
Operating lease liabilities48,353 47,815 
     Total operating lease liabilities$70,396 $67,522 
Finance Leases
Property, plant and equipment, at cost$77 $77 
Accumulated depreciation(26)(10)
     Property, plant and equipment, net$51 $67 
Current installments of finance lease obligations$15 $14 
Finance lease obligations$39 $55 
     Total finance lease obligations$54 $69 
Weighted Average Remaining Lease Term (years)
     Operating leases3.794.07
     Finance leases3.324.32
Weighted Average Discount Rate
     Operating leases7.56 %7.28 %
     Finance leases7.00 %7.00 %
Schedule of Future Minimum Lease Obligations, Finance Lease The Partnership’s future minimum lease obligations as of December 31, 2025 consist of the following:
Operating LeasesFinance Leases
Year 1$28,017 $18 
Year 222,881 18 
Year 315,882 18 
Year 49,482 6 
Year 54,743 — 
Thereafter2,991 — 
     Total83,996 60 
     Less amounts representing interest costs(13,600)(6)
Total lease liability$70,396 $54 
Schedule of Future Minimum Obligations, Operating Leases The Partnership’s future minimum lease obligations as of December 31, 2025 consist of the following:
Operating LeasesFinance Leases
Year 1$28,017 $18 
Year 222,881 18 
Year 315,882 18 
Year 49,482 6 
Year 54,743 — 
Thereafter2,991 — 
     Total83,996 60 
     Less amounts representing interest costs(13,600)(6)
Total lease liability$70,396 $54 
v3.25.4
Fair Value Measurements (Tables)
 12 Months Ended
Dec. 31, 2025
Fair Value Disclosures [Abstract]  
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis
December 31, 2025December 31, 2024
Carrying
Value		Fair
Value		Carrying
Value		Fair
Value
2028 Notes390,795 415,726 386,377 436,172 
Total$390,795 $415,726 $386,377 $436,172 
v3.25.4
Related Party Transactions (Tables)
 12 Months Ended
Dec. 31, 2025
Related Party Transactions [Abstract]  
Schedule of the Impact of Related Party Transactions The impact of related party revenues from sales of products and services is reflected in the Consolidated Statements of Operations as follows:
Revenues:
202520242023
Terminalling and storage
$72,244 $71,799 $72,138 
Transportation
30,428 33,250 29,276 
Sulfur services— 664 — 
Product sales:
Specialty products578 352 8,547 
Sulfur services
3,665 105 220 
4,243 457 8,767 
$106,915 $106,170 $110,181 

    The impact of related party cost of products sold is reflected in the Consolidated Statements of Operations as follows:
Cost of products sold:
Specialty products$28,626 $31,789 $35,930 
Sulfur services
12,885 11,915 11,182 
Terminalling and storage
— 72 75 
$41,511 $43,776 $47,187 
    The impact of related party operating expenses is reflected in the Consolidated Statements of Operations as follows:
Operating expenses:
Transportation
$81,835 $79,441 $73,866 
Sulfur services
5,609 4,888 5,738 
Terminalling and storage
23,725 22,502 21,247 
$111,169 $106,831 $100,851 

    The impact of related party selling, general and administrative expenses is reflected in the Consolidated Statements of Operations as follows:
Selling, general and administrative:
Transportation
$8,533 $11,218 $8,927 
Specialty products4,240 5,454 4,152 
Sulfur services
3,800 5,427 3,714 
Terminalling and storage
1,100 3,051 780 
Indirect overhead allocation, net of reimbursement
14,025 14,235 14,448 
$31,698 $39,385 $32,021 
v3.25.4
Supplemental Balance Sheet Information (Tables)
 12 Months Ended
Dec. 31, 2025
Balance Sheet Related Disclosures [Abstract]  
Schedule of Intangible and Other Assets, Net Components of "Intangibles and other assets, net" at December 31, 2025 and 2024 were as follows:
 20252024
Catalyst and turnaround costs$— $254 
Other intangible assets1 26 
Other1,450 1,229 
 $1,451 $1,509 
Schedule of Other Accrued Liabilities
Components of "Other accrued liabilities" at December 31, 2025 and 2024 were as follows:
 20252024
Accrued interest$17,838 $17,899 
Asset retirement obligations283 — 
Property and other taxes payable3,968 4,043 
Accrued payroll7,119 5,187 
Operating lease liabilities22,043 19,707 
Other28 44 
 $51,279 $46,880 
Schedule of Asset Retirement Obligations
The schedule below summarizes the changes in our asset retirement obligations:
 Year Ended December 31,
 20252024
 (In thousands)
Beginning asset retirement obligations$5,313 $5,182 
Revisions to existing liabilities 1
— — 
Accretion expense121 131 
Liabilities settled(117)— 
Ending asset retirement obligations5,317 5,313 
Current portion of asset retirement obligations 2
(283)— 
Long-term portion of asset retirement obligations 3
$5,034 $5,313 

1 Several factors are considered in the annual review process, including inflation rates, current estimates for removal cost, discount rates, and the estimated remaining useful life of the assets.

2 The current portion of asset retirement obligations is included in "Other accrued liabilities" on the Partnership's Consolidated Balance Sheets.

3 The non-current portion of asset retirement obligations is included in "Other long-term obligations" on the Partnership's Consolidated Balance Sheets.
v3.25.4
Long-Term Debt (Tables)
 12 Months Ended
Dec. 31, 2025
Debt Disclosure [Abstract]  
Schedule of Long-Term Debt At December 31, 2025 and 2024, long-term debt consisted of the following:
20252024
$130,000 1 Credit facility at variable interest rate (7.66% 1 weighted average at December 31, 2025), due November 2027 4 secured by substantially all of the Partnership’s assets, net of unamortized debt issuance costs of $1,787 and $2,242, respectively 2
$37,213 $51,258 
$400,000 Senior notes, 11.5% interest, net of unamortized debt issuance costs of $4,205 and $6,223, respectively, including unamortized discount of $5,000 and $7,400, respectively, due February 2028, secured 2,3,4
390,795 386,377 
Total428,008 437,635 
Less: current portion— — 
Total long-term debt, net of current portion$428,008 $437,635 

    1 The interest rate fluctuates based on Adjusted Term SOFR (set on the date of each advance) or the alternate base rate plus an applicable margin. The margin is set every three months. The applicable margin for revolving loans that are SOFR loans currently ranges from 2.75% to 3.75%, and the applicable margin for revolving loans that are alternate base rate loans currently ranges from 1.75% to 2.75%. The applicable margin for SOFR borrowings and alternate base rate borrowings at December 31, 2025 is 3.75% and 2.75%, respectively. The applicable margin for SOFR borrowings and alternate base rate borrowings effective February 23, 2026 is 3.50% and 2.50%, respectively. The credit facility contains various covenants that limit the Partnership’s ability to make distributions; make certain investments and acquisitions; enter into certain agreements; incur indebtedness; sell assets; and make certain amendments to the Partnership's omnibus agreement with Martin Resource Management Corporation (the "Omnibus Agreement").

    2 The Partnership was in compliance with all debt covenants as of December 31, 2025.
v3.25.4
Partners' Capital (Deficit) (Tables)
 12 Months Ended
Dec. 31, 2025
Equity [Abstract]  
Schedule of Reconciliation of Net Income to Partners Interest in Net Income The following is a reconciliation of net income (loss) allocated to the general partner and limited partners for purposes of calculating net income (loss) attributable to limited partners per unit:
 Years Ended December 31,
 202520242023
   
Net loss$(14,745)$(5,207)$(4,549)
Less general partner’s interest in net loss:
Distributions payable on behalf of general partner interest16 16 16 
General partner interest in undistributed loss(311)(120)(107)
Less loss allocable to unvested restricted units(61)(25)(14)
Limited partners’ interest in net loss$(14,389)$(5,078)$(4,444)

    The following are the unit amounts used to compute the basic and diluted earnings per limited partner unit for the periods presented:
 Years Ended December 31,
 202520242023
Basic weighted average limited partner units outstanding
38,890,039 38,831,355 38,771,657 
Dilutive effect of restricted units issued
— — — 
Total weighted average limited partner diluted units outstanding
38,890,039 38,831,355 38,771,657 
v3.25.4
Unit Based Awards - Long-Term Incentive Plans (Tables)
 12 Months Ended
Dec. 31, 2025
Share-Based Payment Arrangement [Abstract]  
Schedule of Compensation Costs Related to Unit Based Plan Amounts recognized in operating expense and selling, general, and administrative expense in the consolidated financial statements with respect to these plans are as follows:
For the Year Ended December 31,
202520242023
Restricted unit awards
Employees$— $— $— 
Non-employee directors186 187 163 
Phantom unit Awards
Employees2,176 3,070 (177)
Non-employee directors— — — 
   Total unit-based compensation expense$2,362 $3,257 $(14)
Schedule of Restricted Unit Activity A summary of the restricted unit activity for the year ended December 31, 2025 is provided below:
Number of UnitsWeighted Average Grant-Date Fair Value Per Unit
Non-vested, beginning of year168,864 $2.65 
   Granted (TBRU)54,000 $3.62 
   Vested(60,126)$2.75 
   Forfeited— $— 
Non-Vested, end of year162,738 $2.93 
Aggregate intrinsic value, end of year$425 
Schedule of Aggregate Intrinsic Value and Fair Value of Units Vested A summary of the restricted units’ aggregate intrinsic value (market value at vesting date) and fair value of units vested (market value at date of grant) during the years ended December 31, 2025, 2024 and 2023 is provided below:
For the Year Ended
December 31,
202520242023
Aggregate intrinsic value of units vested$55 $46 $89 
Fair value of units vested$165 $168 $178 
v3.25.4
Income Taxes (Tables)
 12 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Components of Income Tax Expense The components of pretax income (loss) and income tax expense (benefit) from operations for the years ended December 31, 2025, 2024 and 2023 are as follows:
202520242023
Income (loss) from continuing operations before income tax expense (benefit)
US$(9,973)$(1,010)$1,369 
Total$(9,973)-9973$(1,010)$1,369 
Income tax expense (benefit) from continuing operations
Current tax expense (benefit)
US federal$2,174 $2,318 $904 
US state and local1,678 1,625 828 
Total current tax expense (benefit)3,852 3,943 1,732 
Deferred tax expense (benefit)
US federal708 595 3,051 
US state and local212 (341)1,135 
Total deferred tax expense (benefit)920 254 4,186 
Total income tax expense (benefit)
US federal2,882 2,913 3,955 
US state and local1,890 1,284 1,963 
Total income tax expense (benefit)$4,772 $4,197 $5,918 
Income Tax Reconciliation
The income tax expense from the Taxable Subsidiary operations for the years ended December 31, 2025, 2024, and 2023 differs from the "expected" tax expense (computed by applying the federal corporate rate of 21% to income before income taxes of the Taxable Subsidiary) as follows:
202520242023
AmountPercentAmountPercentAmountPercent
US federal statutory income tax rate$2,175 21.00 %$2,669 21.00 %$3,880 21.00 %
Domestic federal reconciling items
Nontaxable and nondeductible items, net:
• Insurance premiums paid to non-insurance company
875 8.45 %265 2.08 %280 1.52 %
• Other
36 0.35 %34 0.27 %26 0.15 %
 Return to provision true-up(64)(0.62)%(45)(0.36)%45 0.24 %
 Other domestic federal items16 0.15 %65 0.51 %44 0.24 %
Domestic state and local income taxes, net of federal effect**582 5.62 %284 2.23 %1,203 6.52 %
Effect of changes in tax laws or rates— — %— — %— — %
Total$3,620 34.95 %$3,272 25.73 %$5,478 29.67 %
**State taxes in Texas made up the majority (greater than 50 percent) of the tax effect in this category
Deferred Tax Assets and Liabilities Significant components of deferred tax assets and liabilities at December 31, 2025 and 2024 are as follows:
20252024
Deferred tax assets:
Bad debt reserves$95 $130 
Goodwill and intangibles8,186 9,216 
Employee benefits10 12 
Operating leases54 30 
Interest expense1,426 1,186 
Tax loss carryforwards40 118 
Other185 150 
Subtotal9,996 10,842 
Less: Valuation allowance— — 
Total net deferred tax assets9,996 10,842 
Deferred tax liabilities:
Property and equipment(970)(896)
Operating leases— — 
Total deferred tax liabilities(970)(896)
Net deferred tax assets$9,026 $9,946 
Income Taxes Paid (Net of Refunds Received)
Income taxes paid (net of refunds received) for the years ended December 31, 2025, 2024 and 2023, are as follows:

202520242023
US federal$1,950 $2,340 $560 
Domestic state and local
Florida
*
63 61 
Louisiana
*
56 64 
Tennessee
*
*
59 
Texas1,349 766 510 
Other223 131 150 
Subtotal1,572 1,016 844 
Total$3,522 $3,356 $1,404 
*Jurisdiction is below the five percent disaggregation threshold for the period presented
v3.25.4
Business Segments (Tables)
 12 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
Schedule of Segment Reporting Information, by Segment
The following tables present selected financial information with respect to the Partnership's operating segments for the years ended December 31, 2025, 2024 and 2023.
Terminalling and StorageTransportationSulfur ServicesSpecialty ProductsIndirect selling, general and administrativeTotal
Year Ended December 31, 2025:
Operating revenues from external customers$90,831 $212,509 $164,079 $248,694 $— $716,113 
Intersegment operating revenues 7,456 16,500 — 109 — 24,065 
Total segment revenues98,287 229,009 164,079 248,803 — 740,178 
Reconciliation of revenues:
Elimination of intersegment revenues(7,456)(16,500)— (109)— (24,065)
Total consolidated revenues90,831 212,509 164,079 248,694 — 716,113 
Less: cost of products sold:
Direct product costs— — 87,008 207,556 — 294,564 
Manufacturing costs (plant, labor, transportation, and other)— — 26,758 18,180 — 44,938 
Segment gross margin98,287 229,009 50,313 23,067 — 400,676 
Less:
Employment related expenses2
26,696 60,987 8,636 5,787 12,274 114,380 
Driver pay — 47,071 — — — 47,071 
Pass-through expenses— 23,676 3,199 — — 26,875 
Utilities, materials, and supplies14,352 2,477 965 118 — 17,912 
Repairs and maintenance4,282 17,633 714 15 — 22,644 
Insurance related expenses4,803 17,167 729 168 116 22,983 
Lease expenses4,481 20,737 465 98 — 25,781 
Other segment expenses1
7,807 8,509 5,577 487 3,595 25,975 
Depreciation and amortization21,209 11,768 14,197 3,023 — 50,197 
(Gain) loss on sale or disposition of property, plant and equipment67 (2,057)(15)(34)— (2,039)
83,697 207,968 34,467 9,662 15,985 351,779 
Operating income (loss)$14,590 $21,041 $15,846 $13,405 $(15,985)$48,897 
Segment assets$156,111 $165,129 $132,397 $68,781 $— $522,418 
Capital expenditures and plant turnaround costs$9,833 $8,693 $11,369 $1,726 $— $31,621 
1 Other segment expenses include outside services, property taxes, terminalling fees, regulatory expenses, professional fees, communications expenses, and many other less significant expense categories used in operations.

2 These employment expenses include allocated overhead from Martin Resource Management Corporation and exclude those that are part of our manufacturing operations. Payroll expenses in our manufacturing operations are included in cost of products sold.
Terminalling and StorageTransportationSulfur ServicesSpecialty ProductsIndirect selling, general and administrativeTotal
Year Ended December 31, 2024:
Operating revenues from external customers$89,067 $223,934 $129,771 $264,850 $— $707,622 
Intersegment operating revenues 7,488 15,873 1 95 — 23,457 
Total segment revenues96,555 239,807 129,772 264,945 — 731,079 
Reconciliation of revenues:
Elimination of intersegment revenues(7,488)(15,873)(1)(95)— (23,457)
Total consolidated revenues89,067 223,934 129,771 264,850 — 707,622 
— 
Less: cost of products sold:
Direct product costs— — 58,102 217,866 — 275,968 
Manufacturing costs (plant, labor, transportation, and other)72 — 21,882 19,536 — 41,490 
Segment gross margin96,483 239,807 49,788 27,543 — 413,621 
Less:
Employment related expenses2
25,714 60,882 9,148 5,941 12,267 113,952 
Driver pay — 50,573 — — — 50,573 
Pass-through expenses— 24,454 2,925 — — 27,379 
Utilities, materials, and supplies13,591 2,254 794 137 — 16,776 
Repairs and maintenance5,776 18,219 706 15 — 24,716 
Insurance related expenses6,914 15,083 730 125 825 23,677 
Lease expenses4,268 16,548 414 121 — 21,351 
Other segment expenses1
7,470 9,296 4,473 996 6,464 28,699 
Depreciation and amortization22,757 13,027 11,769 3,234 — 50,787 
(Gain) loss on sale or disposition of property, plant and equipment(1,105)(713)298 (64)— (1,584)
85,385 209,623 31,257 10,505 19,556 356,326 
Operating income (loss)$11,098 $30,184 $18,531 $17,038 $(19,556)$57,295 
Segment assets$180,769 $165,093 $126,074 $66,573 $— $538,509 
Capital expenditures and plant turnaround costs$13,764 $9,188 $26,380 $3,291 $— $52,623 
1 Other segment expenses include outside services, property taxes, terminalling fees, regulatory expenses, professional fees, communications expenses, and many other less significant expense categories used in operations. The Unallocated SG&A amount includes $3,674 in transaction expenses associated with the terminated merger with Martin Resource Management Corporation.

2 These employment expenses include allocated overhead from Martin Resource Management Corporation and exclude those that are part of our manufacturing operations. Payroll expenses in our manufacturing operations are included in cost of products sold.
Terminalling and StorageTransportationSulfur ServicesSpecialty ProductsIndirect selling, general and administrativeTotal
Year Ended December 31, 2023:
Operating revenues from external customers$86,514 $223,677 $140,995 $346,777 $— $797,963 
Intersegment operating revenues 8,945 17,249 — 86 — 26,280 
Total segment revenue95,459 240,926 140,995 346,863 — 824,243 
Reconciliation of revenues:
Elimination of intersegment revenues(8,945)(17,249)— (86)— (26,280)
Total consolidated revenues86,514 223,677 140,995 346,777 — 797,963 
— 
Less: cost of products sold:
Direct product costs— — 75,002 294,005 — 369,007 
Manufacturing costs (plant, labor, transportation, and other)75 — 18,839 25,195 — 44,109 
Segment gross margin95,384 240,926 47,154 27,663 — 411,127 
Less:
Employment related expenses2
23,018 56,244 7,997 5,463 12,755 105,477 
Driver pay — 52,650 — — 52,650 
Pass-through expenses— 27,196 3,657 — 30,853 
Utilities, materials, and supplies16,863 2,134 1,225 157 20,379 
Repairs and maintenance4,259 22,582 340 45 27,226 
Insurance related expenses4,525 14,056 759 122 19,462 
Lease expenses3,779 11,544 375 135 15,833 
Other segment expenses1
7,019 7,715 4,716 1,276 3,275 24,001 
Depreciation and amortization21,030 14,879 10,690 3,296 — 49,895 
(Gain) loss on sale of property, plant and equipment359 (1,775)(17)60 — (1,373)
80,852 207,225 29,742 10,554 16,030 344,403 
Operating income (loss)$14,532 $33,701 $17,412 $17,109 $(16,030)$66,724 
Segment assets$171,320 $161,506 $103,779 $72,770 $— $509,375 
Capital expenditures and plant turnaround costs$13,168 $7,598 $16,851 $2,519 $— $40,136 
1 Other segment expenses include outside services, property taxes, terminalling fees, regulatory expenses, professional fees, communications expenses, and many other less significant expense categories used in operations.

2 These employment expenses include allocated overhead from Martin Resource Management Corporation and exclude those that are part of our manufacturing operations. Payroll expenses in our manufacturing operations are included in cost of products sold.
v3.25.4
Investment in DSM Semichem LLC (Tables)
 12 Months Ended
Dec. 31, 2025
Schedule of Investments [Abstract]  
Schedule of Investment Income
Selected financial information for DSM is as follows:
As of December 31,Year ended December 31,
Total AssetsLong-Term DebtMembers' Equity/Partners' CapitalRevenuesNet Income (Loss)
2025
DSM Semichem LLC$113,007 $25,521 $57,598 $—$(10,916)
2024
DSM Semichem LLC$105,773 $31,700 $68,513 $—$(6,240)
v3.25.4
Organization and Description of Business (Details) - segment
 12 Months Ended
Dec. 28, 2021
Dec. 31, 2025
Schedule of Equity Method Investments    
Number of primary business lines   4
Holdings | Martin Resource Management Corporation    
Schedule of Equity Method Investments    
Ownership percentage 100.00%  
v3.25.4
Significant Accounting Policies and Practices (Details)
 1 Months Ended 12 Months Ended
Aug. 31, 2025
USD ($)
Dec. 31, 2025
USD ($)
segment
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Goodwill and Other Intangibles        
Number of reporting units | segment   4    
Impairment of goodwill $ 0   $ 0 $ 0
Impairment of intangible assets   $ 0 0 0
Debt Issuance Costs        
Debt issuance cost   808,000 23,000 14,289,000
Amortization of debt issuance costs   3,280,000 3,085,000 $ 3,978,000
Accumulated amortization of debt issuance costs   $ 35,677,000 $ 32,397,000  
Minimum        
Deferred Catalyst Costs        
Catalyst, useful life (in months)   12 months    
Deferred Turnaround Costs        
Turnarounds, useful life (in months)   12 months    
Maximum        
Deferred Catalyst Costs        
Catalyst, useful life (in months)   36 months    
Deferred Turnaround Costs        
Turnarounds, useful life (in months)   36 months    
v3.25.4
Exit Activities and Divestitures - Schedule of Revenue and Costs of Disposal Group (Details) - Butane Optimization Business - Disposal Group, Not Discontinued Operations - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations      
Products revenue $ 0 $ 0 $ 70,539
Cost of products sold 0 0 72,283
Selling, general and administrative expenses 0 0 512
Operating income (loss) $ 0 $ 0 $ (2,256)
v3.25.4
Revenue - Disaggregation of Revenue (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Jun. 30, 2023
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disaggregation of Revenue        
Total revenues   $ 716,113 $ 707,622 $ 797,963
Throughput and storage        
Disaggregation of Revenue        
Total revenues [1]   90,831 89,067 86,514
Sulfur services        
Disaggregation of Revenue        
Total revenues   16,441 14,572 13,430
Natural gas liquids product sales        
Disaggregation of Revenue        
Total revenues $ 70,539      
Terminalling and storage segment        
Disaggregation of Revenue        
Total revenues   90,831 89,067 86,514
Terminalling and storage segment | Throughput and storage        
Disaggregation of Revenue        
Total revenues   90,831 89,067 86,514
Transportation segment        
Disaggregation of Revenue        
Total revenues   212,509 223,934 223,677
Transportation segment | Land transportation        
Disaggregation of Revenue        
Total revenues   156,300 165,353 166,717
Transportation segment | Inland transportation        
Disaggregation of Revenue        
Total revenues   46,955 51,826 50,890
Transportation segment | Offshore transportation        
Disaggregation of Revenue        
Total revenues   9,254 6,755 6,070
Sulfur service segment        
Disaggregation of Revenue        
Total revenues   164,079 129,771 140,995
Sulfur service segment | Sulfur product sales        
Disaggregation of Revenue        
Total revenues   38,380 31,347 30,170
Sulfur service segment | Fertilizer product sales        
Disaggregation of Revenue        
Total revenues   109,258 83,852 97,395
Sulfur service segment | Sulfur services        
Disaggregation of Revenue        
Total revenues   16,441 14,572 13,430
Specialty products segment        
Disaggregation of Revenue        
Total revenues   248,694 264,850 346,777
Specialty products segment | Natural gas liquids product sales        
Disaggregation of Revenue        
Total revenues   139,940 144,238 214,713
Specialty products segment | Lubricant product sales        
Disaggregation of Revenue        
Total revenues   $ 108,754 $ 120,612 $ 132,064
[1] Related Party Transactions Included Above
Year Ended December 31,
 202520242023
Revenues:   
Terminalling and storage$72,244 $71,799 $72,138 
Transportation30,428 33,250 29,276 
Sulfur Services— 664 — 
Product sales4,243 457 8,767 
Costs and expenses:   
Cost of products sold: (excluding depreciation and amortization)   
Specialty products28,626 31,789 35,930 
Sulfur services12,885 11,915 11,182 
          Terminalling and storage— 72 75 
Expenses:   
Operating expenses111,169 106,831 100,851 
Selling, general and administrative31,698 39,385 32,021 
v3.25.4
Revenue - Narrative (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Jun. 30, 2023
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disaggregation of Revenue        
Revenues   $ 716,113 $ 707,622 $ 797,963
2026   24,173    
2027   13,022    
2028   12,235    
2029   9,909    
2030   8,334    
Subsequent years   $ 253    
Natural Gas Liquids        
Disaggregation of Revenue        
Revenues $ 70,539      
v3.25.4
Revenue - Estimated Revenue Expected to be Recognized in Future (Details)
$ in Thousands
Dec. 31, 2025
USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 412,976
Throughput and storage | Throughput and storage  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation 295,426
Natural Gas Liquids | Specialty Products  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation 3,934
Product sales | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation 42,711
Service revenues | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation 70,905
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 74,227
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Throughput and storage | Throughput and storage  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 45,672
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Natural Gas Liquids | Specialty Products  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 3,934
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Product sales | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 14,237
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Service revenues | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 10,384
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 68,733
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 | Throughput and storage | Throughput and storage  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 47,042
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 | Natural Gas Liquids | Specialty Products  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 0
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 | Product sales | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 14,237
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 | Service revenues | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 7,454
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 69,644
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 | Throughput and storage | Throughput and storage  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 48,454
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 | Natural Gas Liquids | Specialty Products  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 0
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 | Product sales | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 14,237
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 | Service revenues | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 6,953
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 56,860
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01 | Throughput and storage | Throughput and storage  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 49,907
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01 | Natural Gas Liquids | Specialty Products  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 0
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01 | Product sales | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 0
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01 | Service revenues | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 6,953
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2030-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 54,059
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2030-01-01 | Throughput and storage | Throughput and storage  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 51,404
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2030-01-01 | Natural Gas Liquids | Specialty Products  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 0
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2030-01-01 | Product sales | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 0
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2030-01-01 | Service revenues | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 2,655
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2031-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 89,453
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2031-01-01 | Throughput and storage | Throughput and storage  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 52,947
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2031-01-01 | Natural Gas Liquids | Specialty Products  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 0
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2031-01-01 | Product sales | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 0
Revenue, remaining performance obligation, expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2031-01-01 | Service revenues | Sulfur Services  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction  
Revenue, remaining performance obligation $ 36,506
v3.25.4
Inventories (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Inventory Disclosure [Abstract]    
Natural Gas Liquids $ 1,125 $ 2,814
Sulfur 1,300 1,440
Fertilizer 21,666 18,463
Lubricants 20,281 23,227
Other 5,876 5,763
Inventories $ 50,248 $ 51,707
v3.25.4
Property, Plant, and Equipment - Summary (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Property, Plant and Equipment    
Property, plant and equipment, at cost $ 970,753 $ 954,059
Land    
Property, Plant and Equipment    
Property, plant and equipment, at cost 18,812 18,812
Improvements to land and buildings    
Property, Plant and Equipment    
Property, plant and equipment, at cost $ 142,035 136,609
Improvements to land and buildings | Minimum    
Property, Plant and Equipment    
Depreciable lives (in years) 10 years  
Improvements to land and buildings | Maximum    
Property, Plant and Equipment    
Depreciable lives (in years) 25 years  
Storage equipment    
Property, Plant and Equipment    
Property, plant and equipment, at cost $ 131,707 130,663
Storage equipment | Minimum    
Property, Plant and Equipment    
Depreciable lives (in years) 5 years  
Storage equipment | Maximum    
Property, Plant and Equipment    
Depreciable lives (in years) 50 years  
Marine vessels    
Property, Plant and Equipment    
Property, plant and equipment, at cost $ 201,831 194,406
Marine vessels | Minimum    
Property, Plant and Equipment    
Depreciable lives (in years) 4 years  
Marine vessels | Maximum    
Property, Plant and Equipment    
Depreciable lives (in years) 25 years  
Operating plant and equipment    
Property, Plant and Equipment    
Property, plant and equipment, at cost $ 421,088 396,631
Operating plant and equipment | Minimum    
Property, Plant and Equipment    
Depreciable lives (in years) 3 years  
Operating plant and equipment | Maximum    
Property, Plant and Equipment    
Depreciable lives (in years) 50 years  
Furniture, fixtures and other equipment    
Property, Plant and Equipment    
Property, plant and equipment, at cost $ 7,629 7,908
Furniture, fixtures and other equipment | Minimum    
Property, Plant and Equipment    
Depreciable lives (in years) 3 years  
Furniture, fixtures and other equipment | Maximum    
Property, Plant and Equipment    
Depreciable lives (in years) 20 years  
Transportation equipment    
Property, Plant and Equipment    
Property, plant and equipment, at cost $ 39,115 43,807
Transportation equipment | Minimum    
Property, Plant and Equipment    
Depreciable lives (in years) 3 years  
Transportation equipment | Maximum    
Property, Plant and Equipment    
Depreciable lives (in years) 7 years  
Construction in progress    
Property, Plant and Equipment    
Property, plant and equipment, at cost $ 8,536 $ 25,223
v3.25.4
Property, Plant, and Equipment - Narrative (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Property, Plant and Equipment [Abstract]      
Depreciation expense $ 40,393 $ 41,604 $ 44,700
Amortization of right-of-use assets 15 11 6
Property, plant and equipment, at cost 77 77  
Accumulated amortization associated with capital leases 26 10  
Additions to property, plant and equipment included in accounts payable $ 2,146 $ 2,661 $ 2,943
v3.25.4
Goodwill (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Goodwill    
Carrying amount of goodwill $ 16,671 $ 16,671
Terminalling and storage    
Goodwill    
Carrying amount of goodwill 6,756 6,756
Specialty products    
Goodwill    
Carrying amount of goodwill 4,229 4,229
Sulfur Services    
Goodwill    
Carrying amount of goodwill 5,197 5,197
Transportation    
Goodwill    
Carrying amount of goodwill $ 489 $ 489
v3.25.4
Leases - Narrative (Details)
 12 Months Ended
Dec. 31, 2025
Lessee, Lease, Description  
Termination period ( in years) 1 year
Minimum  
Lessee, Lease, Description  
Remaining lease term (in years) 1 year
Maximum  
Lessee, Lease, Description  
Remaining lease term (in years) 11 years
Renewal term (in years) 5 years
v3.25.4
Leases - Lease Cost (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Leases [Abstract]      
Operating lease cost $ 26,747 $ 22,256 $ 16,198
Finance lease cost:      
Amortization of right-of-use assets 15 11 6
Interest on lease liabilities 4 3 0
Short-term lease cost 5,691 4,748 5,415
Variable lease cost 100 163 191
Total lease cost $ 32,557 $ 27,181 $ 21,810
v3.25.4
Leases - Cash Flow Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Cash paid for amounts included in the measurement of lease liabilities:      
Operating cash flows from operating leases $ 48,374 $ 39,763 $ 29,820
Operating cash flows from finance leases 4 3 0
Financing cash flows from finance leases 14 9 9
Right-of-use assets obtained in exchange for lease obligations:      
Operating leases 23,402 21,133 38,935
Finance leases $ 0 $ 77 $ 0
v3.25.4
Leases - Balance Sheet Information (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Operating Leases    
Operating lease right-of-use assets $ 69,938 $ 67,140
Current portion of operating lease liabilities included in "Other accrued liabilities" 22,043 19,707
Operating lease liabilities 48,353 47,815
Total operating lease liabilities $ 70,396 $ 67,522
Operating Lease, Liability, Current, Statement of Financial Position Other accrued liabilities Other accrued liabilities
Finance Leases    
Property, plant and equipment, at cost $ 77 $ 77
Accumulated depreciation (26) (10)
Property, plant and equipment, net 51 67
Current installments of finance lease obligations 15 14
Finance lease obligations 39 55
Total finance lease obligations $ 54 $ 69
Weighted Average Remaining Lease Term (years)    
Operating leases 3 years 9 months 14 days 4 years 25 days
Finance leases 3 years 3 months 25 days 4 years 3 months 25 days
Weighted Average Discount Rate    
Operating leases 7.56% 7.28%
Finance leases 7.00% 7.00%
v3.25.4
Leases - Future Minimum Lease Obligations (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Operating Leases    
Year 1 $ 28,017  
Year 2 22,881  
Year 3 15,882  
Year 4 9,482  
Year 5 4,743  
Thereafter 2,991  
Total 83,996  
Less amounts representing interest costs (13,600)  
Total lease liability 70,396 $ 67,522
Finance Leases    
Year 1 18  
Year 2 18  
Year 3 18  
Year 4 6  
Year 5 0  
Thereafter 0  
Total 60  
Less amounts representing interest costs (6)  
Total lease liability $ 54 $ 69
v3.25.4
Fair Value Measurements (Details) - Nonrecurring - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Carrying Value    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Senior notes $ 390,795 $ 386,377
Carrying Value | 2028 Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Senior notes 390,795 386,377
Fair Value    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Senior notes 415,726 436,172
Fair Value | 2028 Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Senior notes $ 415,726 $ 436,172
v3.25.4
Related Party Transactions - Narrative (Details)
 12 Months Ended
Dec. 31, 2025
shares
MMGP  
Related Party Transaction  
General partner interest percentage 2.00%
Martin Resource Management | Martin Resource Management Corporation | Martin Midstream Partners L.P.  
Related Party Transaction  
Number of shares owned (in shares) 7,874,446
Voting interest percentage 20.20%
Martin Resource Management | Martin Resource Management | MMGP Holdings, LLC  
Related Party Transaction  
General partner interest percentage 100.00%
Martin Resource Management | MMGP  
Related Party Transaction  
General partner interest percentage 2.00%
v3.25.4
Related Party Transactions - Omnibus Agreement (Details) - Omnibus Agreement - Martin Resource Management - USD ($)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Related Party Transaction      
Noncompete restriction threshold $ 5,000,000    
Noncompete restriction ownership option opportunity threshold minimum 5,000,000    
Noncompete restriction ownership option opportunity threshold minimum with equity limitation $ 5,000,000    
Equity limitation on ownership restriction percentage (less than) 20.00%    
Approved annual reimbursements for indirect expenses $ 13,536,000    
Indirect expenses reimbursed $ 13,536,000 $ 13,508,000 $ 13,982,000
v3.25.4
Related Party Transactions - Master Transportation Services Agreement (Details)
 12 Months Ended
Dec. 31, 2025
Master Transportation Services Agreement | Martin Resource Management  
Related Party Transaction  
Termination written notice, minimum (in days) 30 days
v3.25.4
Related Party Transactions - Terminal Services Agreements (Details)
 12 Months Ended
Dec. 31, 2025
Terminal Services Agreements | Martin Resource Management  
Related Party Transaction  
Termination written notice, minimum (in days) 90 days
v3.25.4
Related Party Transactions - Marine Agreements (Details) - Marine Transportation Agreement - Martin Resource Management
 12 Months Ended
Dec. 31, 2025
Related Party Transaction  
Automatic consecutive term renewal period (in years) 1 year
Termination written notice, minimum (in days) 60 days
v3.25.4
Related Party Transactions - Other Agreements (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
USD ($)
bbl_per_day
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Related Party Transaction      
Annual escalation benchmark, consumer price index (in percent) 67.00%    
Operating cash flows from operating leases $ 48,374 $ 39,763 $ 29,820
East Texas Mack Leases      
Related Party Transaction      
Operating cash flows from operating leases $ 6,721 $ 4,998 $ 3,256
Martin Resource Management | East Texas Mack Leases      
Related Party Transaction      
Ownership interest 47.20%    
Martin Resource Management | Cross Tolling Agreement      
Related Party Transaction      
Production minimum per day (in bbl) | bbl_per_day 6,500    
Martin Resource Management | Storage and Services Agreement      
Related Party Transaction      
Termination written notice, minimum (in days) 90 days    
v3.25.4
Related Party Transactions - Schedule of the Impact of Related Party Transactions (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Revenues:      
Revenues $ 716,113 $ 707,622 $ 797,963
Cost of products sold:      
Cost of products sold 318,623 297,036 389,680
Operating expenses:      
Operating costs and expenses [1] 258,431 255,586 252,211
Selling, general and administrative:      
Selling, general and administrative expenses [1] 42,004 48,502 40,826
Terminalling and storage      
Revenues:      
Revenues [1] 90,831 89,067 86,514
Cost of products sold:      
Cost of products sold [1] 0 72 75
Transportation      
Revenues:      
Revenues [1] 212,509 223,934 223,677
Specialty products      
Revenues:      
Revenues [1] 248,694 264,850 346,777
Cost of products sold:      
Cost of products sold [1] 217,157 228,600 305,903
Product sales      
Revenues:      
Revenues [1] 396,332 380,049 474,342
Sulfur services      
Revenues:      
Revenues [1] 147,638 115,199 127,565
Cost of products sold:      
Cost of products sold [1] 101,466 68,364 83,702
Related Party      
Revenues:      
Revenues 106,915 106,170 110,181
Cost of products sold:      
Cost of products sold 41,511 43,776 47,187
Operating expenses:      
Operating costs and expenses 111,169 106,831 100,851
Selling, general and administrative:      
Selling, general and administrative expenses 31,698 39,385 32,021
Related Party | Indirect overhead allocation, net of reimbursement      
Selling, general and administrative:      
Selling, general and administrative expenses 14,025 14,235 14,448
Related Party | Terminalling and storage      
Revenues:      
Revenues 72,244 71,799 72,138
Related Party | Transportation      
Revenues:      
Revenues 30,428 33,250 29,276
Operating expenses:      
Operating costs and expenses 81,835 79,441 73,866
Selling, general and administrative:      
Selling, general and administrative expenses 8,533 11,218 8,927
Related Party | Specialty products      
Revenues:      
Revenues 578 352 8,547
Cost of products sold:      
Cost of products sold 28,626 31,789 35,930
Selling, general and administrative:      
Selling, general and administrative expenses 4,240 5,454 4,152
Related Party | Product sales      
Revenues:      
Revenues 4,243 457 8,767
Related Party | Sulfur services      
Revenues:      
Revenues 3,665 105 220
Cost of products sold:      
Cost of products sold 12,885 11,915 11,182
Operating expenses:      
Operating costs and expenses 5,609 4,888 5,738
Selling, general and administrative:      
Selling, general and administrative expenses 3,800 5,427 3,714
Related Party | Terminalling and storage      
Cost of products sold:      
Cost of products sold 0 72 75
Operating expenses:      
Operating costs and expenses 23,725 22,502 21,247
Selling, general and administrative:      
Selling, general and administrative expenses 1,100 3,051 780
Related Party | Sulfur Services      
Revenues:      
Revenues $ 0 $ 664 $ 0
[1] Related Party Transactions Included Above
Year Ended December 31,
 202520242023
Revenues:   
Terminalling and storage$72,244 $71,799 $72,138 
Transportation30,428 33,250 29,276 
Sulfur Services— 664 — 
Product sales4,243 457 8,767 
Costs and expenses:   
Cost of products sold: (excluding depreciation and amortization)   
Specialty products28,626 31,789 35,930 
Sulfur services12,885 11,915 11,182 
          Terminalling and storage— 72 75 
Expenses:   
Operating expenses111,169 106,831 100,851 
Selling, general and administrative31,698 39,385 32,021 
v3.25.4
Supplemental Balance Sheet Information - Other Assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Balance Sheet Related Disclosures [Abstract]    
Catalyst and turnaround costs $ 0 $ 254
Other intangible assets 1 26
Other 1,450 1,229
Intangible and other assets, net $ 1,451 $ 1,509
v3.25.4
Supplemental Balance Sheet Information - Other Intangible Assets (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]      
Amortization of intangible assets $ 9,682 $ 9,050 $ 5,006
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity      
2025 8,127    
2026 32    
2027 32    
2028 32    
2029 8    
Subsequent years $ 0    
v3.25.4
Supplemental Balance Sheet Information - Other Accrued Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Balance Sheet Related Disclosures [Abstract]    
Accrued interest $ 17,838 $ 17,899
Asset retirement obligations 283 0
Property and other taxes payable 3,968 4,043
Accrued payroll 7,119 5,187
Operating lease liabilities 22,043 19,707
Other 28 44
Total other accrued liabilities $ 51,279 $ 46,880
v3.25.4
Supplemental Balance Sheet Information - Asset Retirement Obligations (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Asset Retirement Obligation, Roll Forward Analysis    
Beginning asset retirement obligations $ 5,313 $ 5,182
Revisions to existing liabilities 0 0
Accretion expense 121 131
Liabilities settled (117) 0
Ending asset retirement obligations 5,317 5,313
Current portion of asset retirement obligations (283) 0
Long-term portion of asset retirement obligations $ 5,034 $ 5,313
v3.25.4
Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($)
 12 Months Ended
Feb. 23, 2026
Dec. 31, 2025
Dec. 31, 2024
Debt Instrument      
Total long-term debt   $ 428,008,000 $ 437,635,000
Less: current portion   0 0
Total long-term debt, net of current portion   428,008,000 437,635,000
Credit Facility      
Debt Instrument      
Total long-term debt   37,213,000 51,258,000
Maximum borrowing capacity   $ 130,000,000  
Weighted average interest rate   7.66%  
Unamortized debt issuance costs   $ 1,787,000 2,242,000
Credit Facility | SOFR      
Debt Instrument      
Applicable margins (percent)   3.75%  
Credit Facility | SOFR | Subsequent Event      
Debt Instrument      
Applicable margins (percent) 3.50%    
Credit Facility | SOFR | Minimum      
Debt Instrument      
Applicable margins (percent)   2.75%  
Credit Facility | SOFR | Maximum      
Debt Instrument      
Applicable margins (percent)   3.75%  
Credit Facility | Prime Rate | Minimum      
Debt Instrument      
Applicable margins (percent)   1.75%  
Credit Facility | Prime Rate | Maximum      
Debt Instrument      
Applicable margins (percent)   2.75%  
Credit Facility | Base Rate      
Debt Instrument      
Applicable margins (percent)   2.75%  
Credit Facility | Base Rate | Subsequent Event      
Debt Instrument      
Applicable margins (percent) 2.50%    
Senior Notes | Senior Notes 11.5% Due February 2028      
Debt Instrument      
Total long-term debt   $ 390,795,000 386,377,000
Unamortized debt issuance costs   4,205,000 6,223,000
Unamortized premium   5,000,000 $ 7,400,000
Face amount   $ 400,000,000  
Fixed rate cost   11.50%  
v3.25.4
Long-Term Debt - Narrative (Details)
 12 Months Ended
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Sep. 30, 2025
Sep. 24, 2025
USD ($)
Sep. 23, 2025
USD ($)
Jun. 30, 2025
Mar. 31, 2025
Debt Instrument                
Cash paid for interest $ 52,312,000 $ 53,449,000 $ 51,607,000          
Capitalized interest 137,000 $ 1,153,000 $ 310,000          
Letters of credit outstanding, amount $ 645,000              
Revolving Credit Facility | Credit Agreement                
Debt Instrument                
Maximum borrowing capacity         $ 130,000 $ 150,000    
Line of credit facility, covenant terms, minimum interest coverage ratio               1.75
Line of credit facility, covenant terms, maximum leverage ratio       4.75     4.50 4.50
Line of credit facility, covenant terms, maximum first lien leverage ratio 125.00%              
v3.25.4
Partners' Capital (Deficit) - Narrative (Details)
 12 Months Ended
Dec. 31, 2025
shares
Limited Partners' Capital Account  
Common limited partner units (in shares) 39,055,086
Martin Resource Management  
Limited Partners' Capital Account  
Common limited partner units (in shares) 7,874,446
MMGP  
Limited Partners' Capital Account  
General partner interest percentage 2.00%
MMGP | Martin Resource Management  
Limited Partners' Capital Account  
Ownership percentage 20.20%
General partner interest percentage 2.00%
Martin Resource Management Corporation  
Limited Partners' Capital Account  
Ownership percentage 98.00%
v3.25.4
Partners' Capital (Deficit) - Impact on Partners' Capital (Deficit) Related to Transactions Between Entities Under Common Control (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2019
Limited Partners' Capital Account        
Cash distributions $ 797 $ 795 $ 793  
Martin Resource Management Corporation | Martin Resource Management Corporation        
Limited Partners' Capital Account        
Purchase price       $ 552,058
Cash distributions       $ 289,019
v3.25.4
Partners' Capital (Deficit) - Distributions of Available Cash (Details)
 12 Months Ended
Dec. 31, 2025
Equity [Abstract]  
Distribution period (in days) 45 days
v3.25.4
Partners' Capital (Deficit) - Reconciliation of Net Income to Partners Interest in Net Income (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Equity [Abstract]      
Net loss $ (14,745) $ (5,207) $ (4,549)
Less general partner’s interest in net loss:      
Distributions payable on behalf of general partner interest 16 16 16
General partner interest in undistributed loss (311) (120) (107)
Less loss allocable to unvested restricted units (61) (25) (14)
Limited partners’ interest in net loss $ (14,389) $ (5,078) $ (4,444)
Weighted average limited partner units - basic (in shares) 38,890,039 38,831,355 38,771,657
Dilutive effect of restricted units issued (in shares) 0 0 0
Total weighted average limited partner diluted units outstanding (in shares) 38,890,039 38,831,355 38,771,657
v3.25.4
Unit Based Awards - Long-Term Incentive Plans - Schedule of Compensation Costs Relate to Unit Based Plan (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award      
Total unit-based compensation expense $ 2,362 $ 3,257 $ (14)
Employees | Restricted unit awards      
Share-based Compensation Arrangement by Share-based Payment Award      
Total unit-based compensation expense 0 0 0
Employees | Phantom unit Awards      
Share-based Compensation Arrangement by Share-based Payment Award      
Total unit-based compensation expense 2,176 3,070 (177)
Non-employee directors | Restricted unit awards      
Share-based Compensation Arrangement by Share-based Payment Award      
Total unit-based compensation expense 186 187 163
Non-employee directors | Phantom unit Awards      
Share-based Compensation Arrangement by Share-based Payment Award      
Total unit-based compensation expense $ 0 $ 0 $ 0
v3.25.4
Unit Based Awards - Long-Term Incentive Plans - Narrative (Details)
$ in Thousands
 1 Months Ended 12 Months Ended
Jan. 24, 2029
shares
Jan. 24, 2028
shares
Jan. 24, 2027
shares
Jan. 24, 2026
shares
Jul. 16, 2025
shares
Feb. 11, 2025
shares
Jul. 19, 2023
shares
Apr. 20, 2022
shares
Jul. 21, 2021
Feb. 28, 2025
director
shares
Dec. 31, 2025
USD ($)
shares
Dec. 31, 2024
USD ($)
Apr. 19, 2022
shares
May 26, 2017
shares
Share-based Compensation Arrangement by Share-based Payment Award                            
Number of shares authorized (in shares)                           3,000,000
Phantom unit Awards                            
Share-based Compensation Arrangement by Share-based Payment Award                            
Trading days                 20 days          
Shares available for grant (in shares)               5,000,000         2,000,000  
Liabilities related to outstanding awards | $                     $ 4,574 $ 3,480    
Current liabilities related to outstanding awards | $                     2,905 1,073    
Noncurrent liabilities related to outstanding awards | $                     1,669 $ 2,407    
Compensation costs not yet recognized | $                     $ 5,598      
Weighted average period for recognition (in years)                     1 year 11 months 12 days      
Phantom unit Awards | Employees                            
Share-based Compensation Arrangement by Share-based Payment Award                            
Issuance of performance-based restricted units (in shares)         1,275,000 1,210,000 1,179,500 365,000            
Phantom Units Appreciation Rights | Employees                            
Share-based Compensation Arrangement by Share-based Payment Award                            
Issuance of performance-based restricted units (in shares)         420,000 425,000 505,500 1,097,500            
Restricted unit awards                            
Share-based Compensation Arrangement by Share-based Payment Award                            
Number of units vested (in shares)                     60,126      
Restricted unit awards | Non-employee directors                            
Share-based Compensation Arrangement by Share-based Payment Award                            
Vesting period (in years)                     4 years      
April Time Based Restricted Units                            
Share-based Compensation Arrangement by Share-based Payment Award                            
Number of directors receiving grants | director                   3        
April Time Based Restricted Units | Non-employee directors                            
Share-based Compensation Arrangement by Share-based Payment Award                            
Issuance of performance-based restricted units (in shares)                   18,000        
Time Based Restricted Units                            
Share-based Compensation Arrangement by Share-based Payment Award                            
Issuance of performance-based restricted units (in shares)                     54,000      
Compensation costs not yet recognized | $                     $ 301      
Weighted average period for recognition (in years)                     2 years 4 months 17 days      
Scenario, Forecast | April Time Based Restricted Units | Non-employee directors | Subsequent Event                            
Share-based Compensation Arrangement by Share-based Payment Award                            
Number of units vested (in shares) 4,500 4,500 4,500 4,500                    
v3.25.4
Unit Based Awards - Long-Term Incentive Plans - Summary of Restricted Unit Activity (Details)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2025
USD ($)
$ / shares
shares
Restricted unit awards  
Number of Units  
Non-vested, beginning of period, numbers of units (in shares) | shares 168,864
Vested, number of units (in shares) | shares (60,126)
Forfeited, number of units (in shares) | shares 0
Non-vested, end of period, number of units (in shares) | shares 162,738
Weighted Average Grant-Date Fair Value Per Unit  
Non-vested, beginning of period, weighted average grant-date fair value per unit (in dollars per share) | $ / shares $ 2.65
Vested, weighted average grant-date fair value per unit (in dollars per share) | $ / shares 2.75
Forfeited, weighted average grant-date fair value per unit (in dollars per share) | $ / shares 0
Non-vested, end of period, weighted average grant-date fair value per unit (in dollars per share) | $ / shares $ 2.93
Aggregate intrinsic value, end of year | $ $ 425
Time Based Restricted Units  
Number of Units  
Granted, number of units (in shares) | shares 54,000
Weighted Average Grant-Date Fair Value Per Unit  
Granted, weighted average grant-date fair value per unit (in dollars per share) | $ / shares $ 3.62
v3.25.4
Unit Based Awards - Long-Term Incentive Plans - Summary of Aggregate Intrinsic Value and Fair Value of Units Vested (Details) - Restricted unit awards - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award      
Aggregate intrinsic value of units vested $ 55 $ 46 $ 89
Fair value of units vested $ 165 $ 168 $ 178
v3.25.4
Income Taxes - Components of Income Tax Expense (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income (loss) from continuing operations before income tax expense (benefit)      
US $ (9,973) $ (1,010) $ 1,369
Total (9,973) (1,010) 1,369
Current tax expense (benefit)      
US federal 2,174 2,318 904
US state and local 1,678 1,625 828
Total current income tax expense 3,852 3,943 1,732
Deferred tax expense (benefit)      
US federal 708 595 3,051
US state and local 212 (341) 1,135
Total deferred income tax expense (benefit) 920 254 4,186
US federal 2,882 2,913 3,955
US state and local 1,890 1,284 1,963
Total income tax expense (benefit) $ 4,772 $ 4,197 $ 5,918
v3.25.4
Income Taxes - Narrative (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Operating Loss Carryforwards      
US state and local $ 1,890 $ 1,284 $ 1,963
Income tax expense 4,772 4,197 5,918
Income taxes payable 1,580 1,283  
Difference between partnership's tax basis and reported amounts 63,929 69,103  
Federal      
Operating Loss Carryforwards      
Income taxes payable 182    
Domestic state and local      
Operating Loss Carryforwards      
Income taxes payable 1,136 931  
Martin Transportation Inc      
Operating Loss Carryforwards      
Income tax expense 3,620 3,272 5,478
MTI      
Operating Loss Carryforwards      
Income tax expense 3,620 3,272 5,478
Net operating loss carryforwards 859    
Net operating loss carryforwards, subject to expiration 854    
Net operating loss carryforwards, not subject to expiration 5    
MTI | Federal      
Operating Loss Carryforwards      
Income taxes refundable   44  
MTI | Domestic state and local      
Operating Loss Carryforwards      
Income taxes payable 262 352  
Texas      
Operating Loss Carryforwards      
US state and local $ 1,152 $ 925 $ 440
v3.25.4
Income Taxes - Income Tax Reconciliation (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Nontaxable and nondeductible items, net:      
Total income tax expense (benefit) $ 4,772 $ 4,197 $ 5,918
MTI      
Amount      
US federal statutory income tax rate 2,175 2,669 3,880
Nontaxable and nondeductible items, net:      
Insurance premiums paid to non-insurance company 875 265 280
Other 36 34 26
Return to provision true-up (64) (45) 45
Other domestic federal items 16 65 44
Domestic state and local income taxes, net of federal effect** 582 284 1,203
Effect of changes in tax laws or rates 0 0 0
Total income tax expense (benefit) $ 3,620 $ 3,272 $ 5,478
Percent      
US federal statutory income tax rate 21.00% 21.00% 21.00%
Nontaxable and nondeductible items, net:      
Insurance premiums paid to non-insurance company 8.45% 2.08% 1.52%
Other 0.35% 0.27% 0.15%
Return to provision true-up (0.62%) (0.36%) 0.24%
Other domestic federal items 0.15% 0.51% 0.24%
Domestic state and local income taxes, net of federal effect** 5.62% 2.23% 6.52%
Effect of changes in tax laws or rates 0.00% 0.00% 0.00%
Total 34.95% 25.73% 29.67%
v3.25.4
Income Taxes - Income Tax Paid (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income Tax Paid, by Individual Jurisdiction [Line Items]      
US federal $ 1,950 $ 2,340 $ 560
Domestic state and local 1,572 1,016 844
Total 3,522 3,356 1,404
Florida      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
Domestic state and local   63 61
Louisiana      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
Domestic state and local   56 64
Tennessee      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
Domestic state and local     59
Texas      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
Domestic state and local 1,349 766 510
Other      
Income Tax Paid, by Individual Jurisdiction [Line Items]      
Domestic state and local $ 223 $ 131 $ 150
v3.25.4
Income Taxes - Deferred Income Tax Assets and Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Deferred tax assets:    
Bad debt reserves $ 95 $ 130
Goodwill and intangibles 8,186 9,216
Employee benefits 10 12
Operating leases 54 30
Interest expense 1,426 1,186
Tax loss carryforwards 40 118
Other 185 150
Subtotal 9,996 10,842
Less: Valuation allowance 0 0
Total net deferred tax assets 9,996 10,842
Deferred tax liabilities:    
Property and equipment (970) (896)
Operating leases 0 0
Total deferred tax liabilities (970) (896)
Net deferred tax assets $ 9,026 $ 9,946
v3.25.4
Business Segments - Narratives (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
USD ($)
segment
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Business Combination      
Number of reporting units | segment 4    
Revenues $ 716,113 $ 707,622 $ 797,963
Specialty products segment      
Business Combination      
Revenues 248,694 264,850 346,777
One customer | Revenue | Customer concentration risk | Specialty products segment      
Business Combination      
Revenues $ 118,207 $ 122,105 $ 120,171
v3.25.4
Business Segments - Income Statement (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Segment Reporting Information      
Revenues $ (716,113) $ (707,622) $ (797,963)
Depreciation and amortization 50,197 50,787 49,895
(Gain) loss on sale or disposition of property, plant and equipment (2,039) (1,584) (1,373)
Costs and expenses 669,255 651,911 732,612
Operating income 48,897 57,295 66,724
Segment assets 522,418 538,509 509,375
Capital expenditures and plant turnaround costs 31,621 52,623 40,136
Operating Segments      
Segment Reporting Information      
Revenues (740,178) (731,079) (824,243)
Direct product costs 294,564 275,968 369,007
Manufacturing costs (plant, labor, transportation, and other) 44,938 41,490 44,109
Segment gross margin 400,676 413,621 411,127
Employment related expenses 114,380 113,952 105,477
Driver pay 47,071 50,573 52,650
Pass-through expenses 26,875 27,379 30,853
Utilities, materials, and supplies 17,912 16,776 20,379
Repairs and maintenance 22,644 24,716 27,226
Insurance related expenses 22,983 23,677 19,462
Lease expenses 25,781 21,351 15,833
Other segment expenses 25,975 28,699 24,001
Depreciation and amortization 50,197 50,787 49,895
(Gain) loss on sale or disposition of property, plant and equipment (2,039) (1,584) (1,373)
Costs and expenses 351,779 356,326 344,403
Operating income 48,897 57,295 66,724
Elimination of intersegment revenues      
Segment Reporting Information      
Revenues 24,065 23,457 26,280
Indirect selling, general and administrative      
Segment Reporting Information      
Employment related expenses 12,274 12,267 12,755
Insurance related expenses 116 825
Other segment expenses 3,595 6,464 3,275
Costs and expenses 15,985 19,556 16,030
Operating income (15,985) (19,556) (16,030)
Indirect selling, general and administrative | Martin Resource Management Corporation      
Segment Reporting Information      
Other segment expenses   3,674  
Terminalling and storage      
Segment Reporting Information      
Revenues (90,831) (89,067) (86,514)
Terminalling and storage | Operating Segments      
Segment Reporting Information      
Revenues (98,287) (96,555) (95,459)
Direct product costs 0 0 0
Manufacturing costs (plant, labor, transportation, and other) 0 72 75
Segment gross margin 98,287 96,483 95,384
Employment related expenses 26,696 25,714 23,018
Driver pay 0 0 0
Pass-through expenses 0 0 0
Utilities, materials, and supplies 14,352 13,591 16,863
Repairs and maintenance 4,282 5,776 4,259
Insurance related expenses 4,803 6,914 4,525
Lease expenses 4,481 4,268 3,779
Other segment expenses 7,807 7,470 7,019
Depreciation and amortization 21,209 22,757 21,030
(Gain) loss on sale or disposition of property, plant and equipment 67 (1,105) 359
Costs and expenses 83,697 85,385 80,852
Operating income 14,590 11,098 14,532
Segment assets 156,111 180,769 171,320
Capital expenditures and plant turnaround costs 9,833 13,764 13,168
Terminalling and storage | Elimination of intersegment revenues      
Segment Reporting Information      
Revenues 7,456 7,488 8,945
Transportation      
Segment Reporting Information      
Revenues (212,509) (223,934) (223,677)
Transportation | Operating Segments      
Segment Reporting Information      
Revenues (229,009) (239,807) (240,926)
Direct product costs 0 0 0
Manufacturing costs (plant, labor, transportation, and other) 0 0 0
Segment gross margin 229,009 239,807 240,926
Employment related expenses 60,987 60,882 56,244
Driver pay 47,071 50,573 52,650
Pass-through expenses 23,676 24,454 27,196
Utilities, materials, and supplies 2,477 2,254 2,134
Repairs and maintenance 17,633 18,219 22,582
Insurance related expenses 17,167 15,083 14,056
Lease expenses 20,737 16,548 11,544
Other segment expenses 8,509 9,296 7,715
Depreciation and amortization 11,768 13,027 14,879
(Gain) loss on sale or disposition of property, plant and equipment (2,057) (713) (1,775)
Costs and expenses 207,968 209,623 207,225
Operating income 21,041 30,184 33,701
Segment assets 165,129 165,093 161,506
Capital expenditures and plant turnaround costs 8,693 9,188 7,598
Transportation | Elimination of intersegment revenues      
Segment Reporting Information      
Revenues 16,500 15,873 17,249
Sulfur Services      
Segment Reporting Information      
Revenues (164,079) (129,771) (140,995)
Sulfur Services | Operating Segments      
Segment Reporting Information      
Revenues (164,079) (129,772) (140,995)
Direct product costs 87,008 58,102 75,002
Manufacturing costs (plant, labor, transportation, and other) 26,758 21,882 18,839
Segment gross margin 50,313 49,788 47,154
Employment related expenses 8,636 9,148 7,997
Driver pay 0 0 0
Pass-through expenses 3,199 2,925 3,657
Utilities, materials, and supplies 965 794 1,225
Repairs and maintenance 714 706 340
Insurance related expenses 729 730 759
Lease expenses 465 414 375
Other segment expenses 5,577 4,473 4,716
Depreciation and amortization 14,197 11,769 10,690
(Gain) loss on sale or disposition of property, plant and equipment (15) 298 (17)
Costs and expenses 34,467 31,257 29,742
Operating income 15,846 18,531 17,412
Segment assets 132,397 126,074 103,779
Capital expenditures and plant turnaround costs 11,369 26,380 16,851
Sulfur Services | Elimination of intersegment revenues      
Segment Reporting Information      
Revenues 0 1 0
Specialty Products      
Segment Reporting Information      
Revenues (248,694) (264,850) (346,777)
Specialty Products | Operating Segments      
Segment Reporting Information      
Revenues (248,803) (264,945) (346,863)
Direct product costs 207,556 217,866 294,005
Manufacturing costs (plant, labor, transportation, and other) 18,180 19,536 25,195
Segment gross margin 23,067 27,543 27,663
Employment related expenses 5,787 5,941 5,463
Driver pay 0 0 0
Pass-through expenses 0 0 0
Utilities, materials, and supplies 118 137 157
Repairs and maintenance 15 15 45
Insurance related expenses 168 125 122
Lease expenses 98 121 135
Other segment expenses 487 996 1,276
Depreciation and amortization 3,023 3,234 3,296
(Gain) loss on sale or disposition of property, plant and equipment (34) 64 (60)
Costs and expenses 9,662 10,505 10,554
Operating income 13,405 17,038 17,109
Segment assets 68,781 66,573 72,770
Capital expenditures and plant turnaround costs 1,726 3,291 2,519
Specialty Products | Elimination of intersegment revenues      
Segment Reporting Information      
Revenues $ 109 $ 95 $ 86
v3.25.4
Investment in DSM Semichem LLC - Narrative (Details)
$ in Thousands
 12 Months Ended
Apr. 01, 2024
USD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Oct. 19, 2022
a
Summary of Investment Holdings          
Payments to acquire equity method investments   $ 0 $ 6,938 $ 0  
DSM Semichem LLC          
Summary of Investment Holdings          
Equity investment ownership percentage         10.00%
Payments to acquire equity method investments $ 6,500        
Area of land | a         22
v3.25.4
Investment in DSM Semichem LLC - Schedule of Investment Income (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Summary of Investment Holdings      
Total Assets $ 522,418 $ 538,509  
Long-Term Debt 428,008 437,635  
Revenues 716,113 707,622 $ 797,963
Net Income (Loss) (9,973) (1,010) $ 1,369
DSM Semichem LLC      
Summary of Investment Holdings      
Total Assets 113,007 105,773  
Long-Term Debt 25,521 31,700  
Members' Equity/Partners' Capital 57,598 68,513  
Revenues 0 0  
Net Income (Loss) $ (10,916) $ (6,240)  
v3.25.4
Subsequent Events (Details) - Subsequent Event
Jan. 22, 2026
$ / shares
Subsequent Event  
Dividends declared (in dollars per share) $ 0.005
Annualized dividends declared (in dollars per share) $ 0.02