COMPASS MINERALS INTERNATIONAL INC, 10-Q filed on 10/30/2024
Quarterly Report
v3.24.3
Cover Page - shares
9 Months Ended
Jun. 30, 2024
Oct. 25, 2024
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2024  
Document Transition Report false  
Entity File Number 001-31921  
Entity Registrant Name Compass Minerals International, Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 36-3972986  
Entity Address, Address Line One 9900 West 109th Street  
Entity Address, Address Line Two Suite 100  
Entity Address, City or Town Overland Park  
Entity Address, State or Province KS  
Entity Address, Postal Zip Code 66210  
City Area Code 913  
Local Phone Number 344-9200  
Title of 12(b) Security Common stock, $0.01 par value  
Trading Symbol CMP  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   41,449,384
Entity Central Index Key 0001227654  
Current Fiscal Year End Date --09-30  
Document Fiscal Year Focus 2024  
Document Fiscal Period Focus Q3  
Amendment Flag false  
v3.24.3
CONSOLIDATED BALANCE SHEETS - USD ($)
$ in Millions
Jun. 30, 2024
Sep. 30, 2023
Current assets:    
Cash and cash equivalents $ 12.8 $ 38.7
Receivables, less allowance for doubtful accounts of $2.3 at both June 30, 2024 and September 30, 2023 92.3 129.3
Inventories 407.5 399.5
Other current assets 34.4 33.4
Total current assets 547.0 600.9
Property, plant and equipment, net 787.9 852.5
Intangible assets, net 100.8 120.0
Goodwill 5.9 88.8
Other noncurrent assets 153.6 154.7
Total assets 1,595.2 1,816.9
Current liabilities:    
Current portion of long-term debt 6.3 5.0
Accounts payable 69.4 116.8
Accrued salaries and wages 19.7 25.9
Income taxes payable 25.0 16.5
Accrued interest 4.5 12.9
Accrued expenses and other current liabilities 63.5 97.5
Total current liabilities 188.4 274.6
Long-term debt, net of current portion 868.8 800.3
Deferred income taxes, net 59.4 58.4
Other noncurrent liabilities 126.5 162.6
Commitments and contingencies (Note 9)
Stockholders’ equity:    
Common stock: $0.01 par value, 200,000,000 authorized shares; 42,197,964 issued shares at June 30, 2024 and September 30, 2023 0.4 0.4
Additional paid-in capital 418.9 413.1
Treasury stock, at cost — 835,419 shares at June 30, 2024 and 1,038,168 shares at September 30, 2023 (10.2) (8.7)
Retained earnings 50.4 220.9
Accumulated other comprehensive loss (107.4) (104.7)
Total stockholders’ equity 352.1 521.0
Total liabilities and stockholders’ equity $ 1,595.2 $ 1,816.9
v3.24.3
CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)
$ in Millions
Jun. 30, 2024
Sep. 30, 2023
ASSETS    
Allowance for doubtful accounts $ 2.3 $ 2.3
Stockholders’ equity:    
Common stock, par or stated value per share (in dollars per share) $ 0.01 $ 0.01
Common stock, shares authorized (in shares) 200,000,000 200,000,000
Common stock, shares issued (in shares) 42,197,964 42,197,964
Treasury stock, shares (in shares) 835,419 1,038,168
v3.24.3
CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)
shares in Thousands, $ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Sales $ 202.9 $ 207.6 $ 908.6 $ 971.1
Gross profit 32.6 34.6 175.5 189.8
Selling, general and administrative expenses 27.5 33.0 106.5 109.2
Loss on impairments 0.0 0.0 173.4 0.0
Other operating (income) expense (0.8) 2.2 (17.4) 5.4
Operating earnings (loss) 5.9 (0.6) (87.0) 75.2
Other (income) expense:        
Interest income (0.2) (1.7) (0.8) (4.7)
Interest expense 17.2 14.3 50.4 42.4
(Gain) loss on foreign exchange (0.5) 2.3 (1.1) 4.6
Net loss in equity investee 0.0 0.8 0.0 3.1
Gain from remeasurement of equity method investment 0.0 (12.6) 0.0 (12.6)
Other expense, net 0.3 2.7 1.9 3.7
(Loss) earnings before income taxes (10.9) (6.4) (137.4) 38.7
Income tax expense (benefit) 32.7 (42.8) 20.4 24.2
Net (loss) earnings $ (43.6) $ 36.4 $ (157.8) $ 14.5
Basic net (loss) earnings per common share (in dollars per share) $ (1.05) $ 0.88 $ (3.83) $ 0.35
Diluted net (loss) earnings per common share (in dollars per share) $ (1.05) $ 0.88 $ (3.83) $ 0.35
Weighted-average common shares outstanding (in thousands):        
Basic (in shares) 41,342 41,142 41,284 40,663
Diluted (in shares) 41,342 41,142 41,284 40,663
Shipping and handling cost        
Cost $ 53.2 $ 53.8 $ 255.1 $ 291.3
Product cost        
Cost $ 117.1 $ 119.2 $ 478.0 $ 490.0
v3.24.3
CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) EARNINGS - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Statement of Comprehensive Income [Abstract]        
Net (loss) earnings $ (43.6) $ 36.4 $ (157.8) $ 14.5
Other comprehensive income (loss):        
Unrealized gain from change in pension obligations, net of tax of $0.0 for the three months ended June 30, 2024 and 2023, and $(0.2) and $0.0 for the nine months ended June 30, 2024 and 2023, respectively 0.3 0.0 0.7 0.1
Unrealized loss from change in other postretirement benefits, net of tax of $0.0 for the three and nine months ended June 2024 and 2023 (0.1) 0.0 (0.1) 0.0
Unrealized income (loss) on cash flow hedges, net of tax of $0.0 for the three months ended June 30, 2024 and 2023, and $0.0 and $0.3 for the nine months ended June 30, 2024 and 2023, respectively 0.9 2.2 (0.3) (1.7)
Cumulative translation adjustment (4.9) 11.8 (3.0) 26.3
Comprehensive (loss) earnings $ (47.4) $ 50.4 $ (160.5) $ 39.2
v3.24.3
CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) EARNINGS (Parenthetical) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Statement of Comprehensive Income [Abstract]        
Unrealized gain (loss) from change in pension obligations, tax $ 0.0 $ 0.0 $ 0.2 $ 0.0
Unrealized loss, other postretirement benefits, tax 0.0 0.0 0.0 0.0
Unrealized income (loss) on cash flow hedges, tax $ 0.0 $ 0.0 $ 0.0 $ 0.3
v3.24.3
CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($)
$ in Millions
Total
Common Stock
Additional Paid-In Capital
Treasury Stock
Retained Earnings
Accumulated Other Comprehensive Loss
Beginning balance at Sep. 30, 2022 $ 265.2 $ 0.4 $ 152.1   $ 235.3 $ (115.3)
Beginning balance, treasury stock at Sep. 30, 2022       $ (7.3)    
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Comprehensive (loss) income 8.7       (0.3) 9.0
Dividends on common stock (6.3)       (6.3)  
Private placement of common stock 240.7   240.7      
Shares issued for stock units, net of shares withheld for taxes (0.3)     (0.3)    
Stock-based compensation 10.6   10.6      
Ending balance at Dec. 31, 2022 518.6 0.4 403.4   228.7 (106.3)
Ending balance, treasury stock at Dec. 31, 2022       (7.6)    
Beginning balance at Sep. 30, 2022 265.2 0.4 152.1   235.3 (115.3)
Beginning balance, treasury stock at Sep. 30, 2022       (7.3)    
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Comprehensive (loss) income 39.2          
Ending balance at Jun. 30, 2023 542.0 0.4 409.7   231.1 (90.6)
Ending balance, treasury stock at Jun. 30, 2023       (8.6)    
Beginning balance at Dec. 31, 2022 518.6 0.4 403.4   228.7 (106.3)
Beginning balance, treasury stock at Dec. 31, 2022       (7.6)    
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Comprehensive (loss) income (19.9)       (21.6) 1.7
Dividends on common stock (6.3)       (6.3)  
Shares issued for stock units, net of shares withheld for taxes (1.3)   (0.3) (1.0)    
Stock-based compensation 3.1   3.1      
Ending balance at Mar. 31, 2023 494.2 0.4 406.2   200.8 (104.6)
Ending balance, treasury stock at Mar. 31, 2023       (8.6)    
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Comprehensive (loss) income 50.4       36.4 14.0
Dividends on common stock (6.1)       (6.1)  
Stock-based compensation 3.5   3.5      
Ending balance at Jun. 30, 2023 542.0 0.4 409.7   231.1 (90.6)
Ending balance, treasury stock at Jun. 30, 2023       (8.6)    
Beginning balance at Sep. 30, 2023 521.0 0.4 413.1   220.9 (104.7)
Beginning balance, treasury stock at Sep. 30, 2023 (8.7)     (8.7)    
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Comprehensive (loss) income (62.3)       (75.3) 13.0
Dividends on common stock (6.4)       (6.4)  
Shares issued for stock units, net of shares withheld for taxes (0.8)   (0.2) (0.6)    
Stock-based compensation 11.9   11.9      
Ending balance at Dec. 31, 2023 463.4 0.4 424.8   139.2 (91.7)
Ending balance, treasury stock at Dec. 31, 2023       (9.3)    
Beginning balance at Sep. 30, 2023 521.0 0.4 413.1   220.9 (104.7)
Beginning balance, treasury stock at Sep. 30, 2023 (8.7)     (8.7)    
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Comprehensive (loss) income (160.5)          
Ending balance at Jun. 30, 2024 352.1 0.4 418.9   50.4 (107.4)
Ending balance, treasury stock at Jun. 30, 2024 (10.2)     (10.2)    
Beginning balance at Dec. 31, 2023 463.4 0.4 424.8   139.2 (91.7)
Beginning balance, treasury stock at Dec. 31, 2023       (9.3)    
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Comprehensive (loss) income (50.8)       (38.9) (11.9)
Dividends on common stock (6.3)       (6.3)  
Shares issued for stock units, net of shares withheld for taxes (1.0)   (0.2) (0.8)    
Stock-based compensation (4.9)   (4.9)      
Ending balance at Mar. 31, 2024 400.4 0.4 419.7   94.0 (103.6)
Ending balance, treasury stock at Mar. 31, 2024       (10.1)    
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Comprehensive (loss) income (47.4)       (43.6) (3.8)
Shares issued for stock units, net of shares withheld for taxes (0.2)   (0.1) (0.1)    
Stock-based compensation (0.7)   (0.7)      
Ending balance at Jun. 30, 2024 352.1 $ 0.4 $ 418.9   $ 50.4 $ (107.4)
Ending balance, treasury stock at Jun. 30, 2024 $ (10.2)     $ (10.2)    
v3.24.3
CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares
3 Months Ended
Mar. 20, 2024
Dec. 20, 2023
Mar. 31, 2024
Dec. 31, 2023
Jun. 30, 2023
Mar. 31, 2023
Dec. 31, 2022
Statement of Stockholders' Equity [Abstract]              
Cash dividends per share (in dollars per share) $ 0.15 $ 0.15 $ 0.15 $ 0.15 $ 0.15 $ 0.15 $ 0.15
v3.24.3
CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)
$ in Millions
9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Cash flows from operating activities:    
Net (loss) earnings $ (157.8) $ 14.5
Adjustments to reconcile net (loss) earnings to net cash flows provided by operating activities:    
Depreciation, depletion and amortization 78.4 72.7
Amortization of deferred financing costs 1.9 2.5
Early extinguishment of debt 0.0 1.1
Stock-based compensation 6.3 17.2
Deferred income taxes 1.2 (4.8)
Unrealized foreign exchange (gain) loss (0.5) 4.5
Loss on impairments 173.4 0.0
Net loss in equity investees 0.0 3.1
Net gain from remeasurement of contingent consideration (23.1) 0.0
Gain from remeasurement of equity method investment 0.0 (12.6)
Other, net 2.6 3.3
Changes in operating assets and liabilities:    
Receivables 36.8 73.7
Inventories (9.9) (28.1)
Other assets (2.0) 9.7
Accounts payable and accrued expenses and other current liabilities (69.4) (13.7)
Other liabilities (10.8) (16.2)
Net cash provided by operating activities 27.1 126.9
Cash flows from investing activities:    
Capital expenditures (93.3) (84.5)
Acquisition of business, net of cash acquired 0.0 (18.9)
Other, net (1.7) (2.5)
Net cash used in investing activities (95.0) (105.9)
Cash flows from financing activities:    
Proceeds from revolving credit facility borrowings 359.6 66.7
Principal payments on revolving credit facility borrowings (289.2) (218.2)
Proceeds from issuance of long-term debt 69.4 237.5
Principal payments on long-term debt (70.3) (311.7)
Payments for contingent consideration (9.1) 0.0
Net proceeds from private placement of common stock 0.0 240.7
Dividends paid (12.7) (18.7)
Deferred financing costs (2.1) (3.9)
Shares withheld to satisfy employee tax obligations (2.0) (1.6)
Other, net (1.4) (0.9)
Net cash provided by (used in) financing activities 42.2 (10.1)
Effect of exchange rate changes on cash and cash equivalents (0.2) 1.0
Net change in cash and cash equivalents (25.9) 11.9
Cash and cash equivalents, beginning of the year 38.7 46.1
Cash and cash equivalents, end of period 12.8 58.0
Supplemental cash flow information:    
Interest paid, net of amounts capitalized 56.5 50.2
Income taxes paid, net of refunds 21.6 11.9
Net change to property, plant and equipment through accounts payable and accrued expenses and other current liabilities $ 16.8 $ (8.3)
v3.24.3
Accounting Policies and Basis of Presentation
9 Months Ended
Jun. 30, 2024
Accounting Policies [Abstract]  
Accounting Policies and Basis of Presentation Accounting Policies and Basis of Presentation:
Compass Minerals International, Inc. (“CMI”), through its subsidiaries (collectively, the “Company”), is a leading global provider of essential minerals focused on safely delivering where and when it matters to help solve nature’s challenges for customers and communities. The Company’s salt products help keep roadways safe during winter weather and are used in numerous other consumer, industrial, chemical and agricultural applications. Its plant nutrition business is the leading North American producer of sulfate of potash (“SOP”), which is used in the production of specialty fertilizers for high-value crops and turf and helps improve the quality and yield of crops, while supporting sustainable agriculture. The Company’s principal products are salt, consisting of sodium chloride and magnesium chloride, and SOP. The Company is also working to develop long-term fire-retardant solutions to help combat wildfires. Additionally, the Company had been pursuing the development of a sustainable lithium salt resource to support the North American battery market. However, as described in Note 5, the Company has terminated its pursuit of the lithium development. The Company’s production sites are located in the United States (“U.S.”), Canada and the United Kingdom (“U.K.”). The Company also provides records management services in the U.K. Except where otherwise noted, references to North America include only the continental U.S. and Canada, and references to the U.K. include only England, Scotland and Wales. References to “Compass Minerals,” “our,” “us” and “we” refer to CMI and its consolidated subsidiaries.
 
CMI is a holding company with no significant operations other than those of its wholly-owned subsidiaries. The consolidated financial statements include the accounts of CMI and its wholly-owned domestic and foreign subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.

The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete consolidated financial statements. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements of the Company for the annual period ended September 30, 2023, as filed with the Securities and Exchange Commission (the “SEC”) in its Amended Annual Report on Form 10-K/A on October 29, 2024 (“2023 Form 10-K/A”). Certain amounts in prior periods have been reclassified to conform to the current period presentation. In the opinion of management, all adjustments, consisting of normal recurring adjustments considered necessary for a fair presentation, have been included.
 
The Company experiences a substantial amount of seasonality in its sales, including its salt deicing product sales. Consequently, Salt segment sales and operating income are generally higher in the first and second fiscal quarters (ending December 31 and March 31) and lower during the third and fourth fiscal quarters (ending June 30 and September 30). In particular, sales of highway and consumer deicing salt and magnesium chloride products vary based on the severity of the winter conditions in areas where the products are used. Following industry practice in North America and the U.K., the Company seeks to stockpile sufficient quantities of deicing salt throughout the first, third and fourth fiscal quarters (ending December 31, June 30 and September 30) to meet the estimated requirements for the winter season. Production of deicing salt can also vary based on the severity or mildness of the preceding winter season. Due to the seasonal nature of the deicing product lines, operating results for the interim periods are not necessarily indicative of the results that may be expected for the full fiscal year. The Company’s plant nutrition business is also seasonal. As a result, the Company and its customers generally build inventories during the plant nutrition business’ low demand periods of the year (which are typically winter and summer, but can vary due to weather and other factors) to ensure timely product availability during the peak sales seasons (which are typically spring and autumn, but can also vary due to weather and other factors). Lastly, the results of the Company’s fire retardant business are also seasonal with peak demand for fire retardant products and services occurring from June through September.

The Company previously identified various misstatements related to (i) certain contingent consideration associated with the Company’s acquisition of Fortress North America, LLC (“Fortress”), (ii) historical understatement of work-in-process inventory, (iii) immaterial misstatements to reclassify the impacts of non-cash capital expenditures in accounts payable in its operating and investing cash flows, (iv) an error in its interim non-GAAP Adjusted EBITDA calculation, which resulted in an understatement of its consolidated Adjusted EBITDA for the first and second quarters of 2024, and (v) certain other individual immaterial misstatements that were also immaterial in the aggregate. These misstatements were corrected via amendments to the Company’s Annual Report on Form 10-K for the period ended September 30, 2023, 2022 and 2021 and its Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2024, both filed on October 29, 2024.
Impairments

As a result of a sustained decrease in the Company’s publicly quoted share price and market capitalization continuing into fiscal 2024 and recent developments related to its magnesium chloride-based fire retardants impacting its Fortress business, the Company determined in the second quarter of fiscal 2024 that there were indicators of impairment and therefore performed long-lived assets and goodwill impairment testing. The analysis for Plant Nutrition resulted in no long-lived asset impairment but did result in a goodwill impairment, as discussed further below. The Fortress analysis resulted in an impairment of the Company’s magnesium chloride-related assets and goodwill; see below for additional details.

On March 22, 2024, the Company was notified of the decision by the U.S. Forest Service that the Company would not be awarded a contract to supply its magnesium chloride-based aerial fire retardant for the calendar 2024 fire season. For purposes of the long-lived asset impairment evaluation, management grouped and tested the magnesium chloride-related assets given their unique classification and separately identifiable cash flows. As a result of the evaluation using the income approach, the Company impaired all magnesium chloride-related assets which resulted in a long-lived asset, net, impairment of $15.6 million (finite-lived intangible assets) and an impairment of $2.4 million of inventory for the nine months ended June 30, 2024. The long-lived asset impairment is included in loss on impairments, while the inventory impairment is reflected in product cost, both on the Consolidated Statements of Operations. The undiscounted cash flows for the remaining Fortress assets were greater than their carrying value resulting in no incremental impairment. Management will continue to monitor events and circumstances that would require a future test of recoverability on the remaining Fortress long-lived assets.

The Company performed the interim goodwill impairment tests consistent with its approach for annual impairment testing, including using similar models, inputs and assumptions. As a result of the interim goodwill impairment test in the second quarter of fiscal 2024, the Company recognized impairment charges totaling $83.0 million included in loss on impairments, on the Consolidated Statements of Operations for the nine months ended June 30, 2024. Goodwill impairment of $51.0 million was related to the Company’s Plant Nutrition segment, primarily due to decreases in projected future revenues and cash flows and an increase in discount rates due to the uncertain regulatory environment in Utah. The remaining goodwill impairment of $32.0 million was related to the Company’s Fortress reporting unit (included in the Corporate and Other segment), primarily due to changes in assumptions surrounding the magnesium chloride-based fire retardants which impacted projected future revenues and cash flows. Following the impairment charges, there is no remaining goodwill balance for the Plant Nutrition and Fortress reporting units. Refer to Note 6 for a summary of goodwill by segment. A summary of the impairments incurred for the nine months ended June 30, 2024, is detailed below (in millions):
Impairment
Financial Statement Line Item
Segment
Nine Months Ended
June 30, 2024
Lithium long-lived assets, net
Loss on impairments
Corporate & Other
$74.8 
Plant Nutrition goodwill
Loss on impairments
Plant Nutrition
51.0 
Fortress goodwill
Loss on impairments
Corporate & Other32.0 
Fortress long-lived assets, net
Loss on impairments
Corporate & Other15.6 
Fortress inventory
Product cost
Corporate & Other2.4 
Total
$175.8 

In connection with the aforementioned impairments, the Company determined the estimated fair value for each reporting unit based on discounted cash flow projections (income approach), market values for comparable businesses (market approach) or a combination of both. Under the income approach, the Company is required to make judgments about appropriate discount rates, long-term revenue growth rates and the amount and timing of expected future cash flows. The cash flows used in its estimates are based on the reporting unit's forecast, long-term business plan, and recent operating performance. Discount rate assumptions are based on an assessment of the risk inherent in the future cash flows of the respective reporting unit and market conditions. The Company’s estimates may differ from actual future cash flows. The risk adjusted discount rate used is consistent with the weighted average cost of capital of the Company’s peer companies and is intended to represent a rate of return that would be expected by a market participant. Under the market approach, market multiples are derived from market prices of stocks of companies in the Company’s peer group. The appropriate multiple is applied to the forecasted revenue and earnings before interest, taxes, depreciation and amortization of the reporting unit to obtain an estimated fair value.

The most critical assumptions used in the calculation of the fair value of each reporting unit are the projected revenue growth rates, long-term operating margin, terminal growth rates, discount rate, and the selection of market multiples. The projected long term operating margin utilized in the Company’s fair value estimates is consistent with its operating plan and is dependent
on the successful execution of its long-term business plan, overall industry growth rates and the competitive environment. The discount rate could be adversely impacted by changes in the macroeconomic environment and volatility in the equity and debt markets. Although management believes its estimate of fair value is reasonable, if the future financial performance falls below expectations or there are unfavorable revisions to significant assumptions, or if the Company’s market capitalization declines, an additional non-cash goodwill or long-lived asset impairment charge may be required in a future period.

Significant Accounting Policies

The Company’s significant accounting policies are detailed in “Note 2 – Summary of Significant Accounting Policies” within Part II, Item 8 of its 2023 Form 10-K/A. There were no material changes in the Company’s significant accounting policies from those described in its 2023 Form 10-K/A.

Recent Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures”, which updates reportable segment disclosure requirements primarily to include enhanced disclosures about significant segment expenses. The amendments are effective for fiscal years beginning after December 15, 2023, and for interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. The amendments should be applied retrospectively to all prior periods presented in the financial statements. Management is currently evaluating this ASU to determine its impact on the Company's disclosures.

In December 2023, the FASB issued ASU 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures”, which updates income tax disclosures by requiring consistent categories and additional disaggregation of information in the rate reconciliation and income taxes paid by jurisdiction. The amendments are effective for fiscal years beginning after December 15, 2024. Early adoption is permitted. The amendments should be applied prospectively; however, retrospective application is permitted. Management is currently evaluating this ASU to determine its impact on the Company’s disclosures.
v3.24.3
Business Acquisition
9 Months Ended
Jun. 30, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]  
Business Acquisition Business Acquisition:
Beginning in 2020, the Company began a series of equity investments in Fortress, a next-generation fire retardant business dedicated to developing and producing a portfolio of fire retardant products to help combat wildfires. On May 5, 2023, the Company acquired the remaining 55% interest in Fortress not previously owned in exchange for an initial cash payment of $18.9 million (net of cash held by Fortress of $6.5 million), and additional contingent consideration of up to $28 million to be paid in cash and/or Compass Minerals common stock upon the achievement of certain performance measures over the next five years, and a cash earn-out based on volumes of certain Fortress fire retardant products sold over a 10-year period. Building upon the previous 45% minority ownership stake in Fortress, the transaction provided the Company full ownership of all Fortress assets, contracts, and intellectual property. See Note 1 for impairment information. See Note 13 for fair value information related to the contingent consideration as of June 30, 2024.
v3.24.3
Revenues
9 Months Ended
Jun. 30, 2024
Revenue from Contract with Customer [Abstract]  
Revenues Revenues:
Deferred Revenue

Deferred revenue represents billings under non-cancellable contracts before the related product or service is transferred to the customer. The portion of deferred revenue that is anticipated to be recognized as revenue during the succeeding twelve-month period is recorded in accrued expenses and other current liabilities on the Consolidated Balance Sheets. Deferred revenue as of June 30, 2024 and September 30, 2023 was approximately $3.6 million and $8.5 million, respectively.

See Note 10 for a disaggregation of sales by segment, type and geographical region.
v3.24.3
Inventories
9 Months Ended
Jun. 30, 2024
Inventory Disclosure [Abstract]  
Inventories Inventories:
 
Inventories consist of the following (in millions):
 June 30,
2024
September 30,
2023
Finished goods$315.3 $319.3 
Work in process
7.3 7.3 
Raw materials and supplies(a)
84.9 72.9 
Total inventories
$407.5 $399.5 
(a)Excludes certain raw materials and supplies of $35.6 million and $35.8 million as of June 30, 2024 and September 30, 2023, respectively, that are not expected to be consumed within the next twelve months, included in Other noncurrent assets in the Consolidated Balance Sheets.
v3.24.3
Property, Plant and Equipment, Net
9 Months Ended
Jun. 30, 2024
Property, Plant and Equipment [Abstract]  
Property, Plant and Equipment, Net Property, Plant and Equipment, Net:
 
Property, plant and equipment, net, consists of the following (in millions):
 June 30,
2024
September 30,
2023
Land, buildings and structures, and leasehold improvements$552.6 $547.9 
Machinery and equipment1,127.9 1,102.0 
Office furniture and equipment22.4 21.6 
Mineral interests169.2 169.1 
Construction in progress68.0 113.3 
 1,940.1 1,953.9 
Less: accumulated depreciation and depletion(1,152.2)(1,101.4)
Property, plant and equipment, net$787.9 $852.5 

The Company had been pursuing the development of a sustainable lithium salt resource to support the North American battery market. The passage of Utah House Bill 513 in March 2023 and the subsequent rulemaking process altered certain aspects of the regulatory landscape that will govern the development of lithium at the Great Salt Lake, introducing uncertainty into how development would proceed. As previously disclosed in the Company’s 2023 Form 10-K/A, the Company indefinitely paused new investment in its lithium development project pending greater clarity on the evolving regulatory environment in Utah. In December of 2023, a revised draft of the aforementioned rulemaking was published that continued to be, in the Company's assessment, adverse to its lithium development project. In addition, in December of 2023, the Company further refined its engineering estimates that, taken together with the proposed rules and decline in market price for lithium products, would result in inadequate risk-adjusted returns on capital.
On January 23, 2024, the Company severed certain members of its lithium development team and terminated its pursuit of the lithium development. Consequently, the Company evaluated the capitalized assets, including site preparation, project engineering, equipment and materials and capitalized labor and interest. As a result, the Company has recorded an impairment charge of $74.8 million for the nine months ended June 30, 2024, including $5.3 million associated with future commitments as of June 30, 2024. The impairments were recorded to reflect the assets at their estimated fair value, considering equipment expected to be used by the on-going business and amounts estimated to be recoverable through returns or salvage value. Prior to recognizing an impairment, the Company had capitalized $72.7 million to its property, plant and equipment on its Consolidated Balance Sheet and has approximately $5.1 million remaining as of June 30, 2024, included in inventory. The Company engaged a valuation specialist to assist in determining the appropriate fair value of the lithium assets and the resulting impairment charge in the first quarter of fiscal 2024. Given the assets are likely to either be used in other operations or liquidated at a later date, the Company utilized a market-based approach that relied on Level 3 inputs (see Note 13 for a discussion of the levels in the fair value hierarchy).
v3.24.3
Goodwill and Intangible Assets
9 Months Ended
Jun. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill and Intangible Assets Goodwill and Intangible Assets:
Changes in the carrying amount of goodwill are summarized as follows (in millions):
Plant Nutrition
Corporate & Other
Consolidated
Balance as of September 30, 2023$51.1 $37.7 $88.8 
Foreign currency translation adjustment0.2 0.2 0.4 
Balance as of December 31, 202351.3 37.9 89.2 
Foreign currency translation adjustment(0.3)— (0.3)
Impairments(51.0)(32.0)(83.0)
Balance as of March 31, 2024— 5.9 5.9 
Foreign currency translation adjustment— — — 
Balance as of June 30, 2024
$— $5.9 $5.9 

In the second quarter of fiscal 2024, there were indicators necessitating an interim impairment test of the Company’s goodwill based on the Company’s review of its operating performance, among other factors, for the relevant reporting units. Refer to Note 1 for additional details. In addition to the Plant Nutrition and Fortress impairments, the remaining change in goodwill between September 30, 2023 and June 30, 2024, was due to the impact from translating foreign-denominated amounts to U.S. dollars.

In connection with the Fortress acquisition described in Note 2, the Company acquired identifiable intangible assets which consisted of customer relationships, developed technology, in-process research and development and trade name. The fair values were determined using Level 3 inputs (see Note 13 for a discussion of the levels in the fair value hierarchy). Upon acquisition, the fair value of the customer relationships was estimated using an income approach method while the fair values of developed technology, in-process research and development and trade name were estimated using the relief from royalty method.

As a result of the Fortress-related impairments discussed in Note 1, the Company impaired all magnesium chloride-related assets which resulted in an impairment of the Company’s developed technology intangible asset of $15.6 million, net of accumulated amortization of $0.4 million. The Company continues to have Fortress-related net intangible assets consisting of customer relationships and trade name of $54.6 million and $0.2 million, respectively, as of June 30, 2024. The Company also has $2.2 million of indefinite-lived in-process research and development recognized in connection with the Fortress acquisition as of June 30, 2024, which will be reviewed for impairment at least annually, or in the event of indicators of impairment, until product development is completed.
v3.24.3
Income Taxes
9 Months Ended
Jun. 30, 2024
Income Tax Disclosure [Abstract]  
Income Taxes Income Taxes:
The Company’s effective income tax rate differs from the U.S. statutory federal income tax rate primarily due to U.S. statutory depletion, state income taxes (net of federal tax benefit), nondeductible executive compensation over $1 million, foreign income, mining and withholding taxes, base erosion and anti-abuse tax, and valuation allowances recorded on deferred tax assets.

The effective tax rates applied to the three and nine months ended June 30, 2024 were determined by excluding the U.S. losses from the overall estimated annual effective tax rate computations and a separate estimated annual effective tax rate was computed and applied to the ordinary U.S. losses.

Management assesses the available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit use of the existing deferred tax assets. A significant piece of objective negative evidence evaluated was the cumulative loss incurred in the U.S. over the three-year period ended June 30, 2024. Such objective evidence limits the ability to consider other subjective evidence, such as the Company’s projections for future income. On the basis of this evaluation, during the nine months ended June 30, 2024, an additional valuation allowance of $28.0 million has been recorded to recognize only the portion of the U.S. deferred tax assets that is more likely than not to be realized. The additional valuation allowance is primarily the result of impairments recognized during the nine months ended June 30, 2024. The amount of the deferred tax assets considered realizable, however, could be adjusted if objective negative evidence in the form of cumulative losses is no longer present and additional weight is given to subjective evidence such as the Company’s projections for income.
As of June 30, 2024 and September 30, 2023, the Company had $65.5 million and $65.4 million, respectively of gross federal NOL carryforwards that have no expiration date and $2.9 million at June 30, 2024 and September 30, 2023 of net operating tax-effected state NOL carryforwards which expire beginning in 2035.

Other current assets in the Consolidated Balance Sheet as of June 30, 2024 and September 30, 2023, consist principally of prepaid expenses, including prepaid tax assets of $11.2 million and $11.0 million, respectively.

Canadian provincial tax authorities have challenged tax positions claimed by one of the Company’s Canadian subsidiaries and have issued tax reassessments for fiscal years 2002-2018. The reassessments are a result of ongoing audits and total $190.4 million, including interest, through June 30, 2024. The Company disputes these reassessments and will continue to work with the appropriate authorities in Canada to resolve the dispute. There is a reasonable possibility that the ultimate resolution of this dispute, and any related disputes for other open tax years, may be materially higher or lower than the amounts the Company has reserved for such disputes. In connection with this dispute, local regulations require the Company to post security with the tax authority until the dispute is resolved. The Company has posted collateral in the form of a $160.1 million performance bond and has paid $36.3 million to the Canadian tax authorities (most of which is recorded in other assets in the Consolidated Balance Sheets at June 30, 2024, and September 30, 2023), which is necessary to proceed with future appeals or litigation.
 
The Company expects that it will be required by local regulations to provide security for additional interest on the above unresolved disputed amounts and for any future reassessments issued by these Canadian tax authorities in the form of cash, letters of credit, performance bonds, asset liens or other arrangements agreeable with the tax authorities until the disputes are resolved.

The Company expects that the ultimate outcome of these matters will not have a material impact on its results of operations or financial condition. However, the Company can provide no assurance as to the ultimate outcome of these matters, and the impact could be material if they are not resolved in the Company’s favor. As of June 30, 2024, the Company believes it has adequately reserved for these reassessments.
 
Additionally, the Company has other uncertain tax positions as well as assessments and disputed positions with taxing authorities in its various jurisdictions, which are consistent with those matters disclosed in the Company’s 2023 Form 10-K/A.
v3.24.3
Long-Term Debt
9 Months Ended
Jun. 30, 2024
Debt Disclosure [Abstract]  
Long-Term Debt Long-Term Debt:
 
Long-term debt consists of the following (in millions):
 June 30,
2024
September 30,
2023
6.75% Senior Notes due December 2027
$500.0 $500.0 
Term Loan due May 2028195.0 198.8 
Revolving Credit Facility due May 2028151.9 81.5 
AR Securitization Facility expires March 202733.8 30.9 
880.7 811.2 
Less unamortized debt issuance costs(5.6)(5.9)
Total debt875.1 805.3 
Less current portion(6.3)(5.0)
Long-term debt$868.8 $800.3 

On March 27, 2024, the Company entered into an amendment to its 2023 Credit Agreement, which eased the restrictions of certain covenants contained in the agreement. The amendment included increasing the maximum allowed consolidated total net leverage ratio (as defined and calculated under the terms of the amended 2023 Credit Agreement) to 6.5x as of the last day of any quarter through the fiscal quarter ended December 31, 2024, then gradually stepping down to 4.75x by the fiscal quarter ended March 31, 2026 and thereafter. The amendment also removed the flexibility related to the lithium development joint ventures, projects or similar arrangements and any related funding transactions in connection therewith. In connection with this amendment, the Company paid fees totaling $1.7 million which were capitalized as deferred financing costs. Additional arrangement and legal fees of $0.9 million were expensed as of March 31, 2024.
On March 27, 2024, certain of the Company’s U.S. subsidiaries entered into an amendment to its revolving accounts receivable financing facility (the “AR Facility”) with PNC Bank, National Association, extending the facility to March 2027. In connection with this amendment, the Company paid fees totaling $0.4 million which were capitalized as deferred financing costs.

As of June 30, 2024, the term loan and revolving credit facility under the 2023 Credit Agreement were secured by substantially all existing and future U.S. assets of the Company, the Goderich mine in Ontario, Canada and capital stock of certain subsidiaries. As of June 30, 2024 and September 30, 2023, the weighted average interest rate on all borrowings outstanding under the 2023 Credit Agreement was approximately 8.0% and 7.8%, respectively. Depending on the type, borrowings under the 2023 Credit Agreement accrue interest at a rate per annum equal to the Adjusted Term SOFR Rate, the Adjusted EURIBO Rate, Prime Rate or the CDO Rate (as defined in the credit agreement), as applicable, plus Applicable Margins (as defined in the credit agreement) which resulted in interest rates between 7.9% and 10.0% as of June 30, 2024, and 7.7% and 9.8% as of September 30, 2023.

As of June 30, 2024, the Company had $208.0 million of availability under its $375 million revolving credit facility. The 2023 Credit Agreement requires the Company to maintain certain financial ratios, including a minimum interest coverage ratio and a maximum total net leverage ratio. The Company was in compliance as of June 30, 2024 with its debt covenants under the 2023 Credit Agreement and its AR Securitization Facility. The consolidated total net leverage ratio represents the ratio of (a) consolidated total net debt to (b) consolidated adjusted earnings before interest, taxes, depreciation and amortization. Consolidated total net debt includes the aggregate principal amount of total debt, net of unrestricted cash not to exceed $75.0 million.

On August 12, 2024, the Company entered into amendments to its 2023 Credit Agreement and its AR Facility, which extended the deadline for delivery of the Company’s June 30, 2024 financial statements for the quarter ended June 30, 2024, together with the respective compliance certificates, from 45 days to 75 days after the last day of the quarter ended June 30, 2024.

On September 13, 2024, the Company entered into amendments to its 2023 Credit Agreement and its AR Facility, which extended the deadline for delivery of the Company’s June 30, 2024 financial statements for the quarter ended June 30, 2024, together with the respective compliance certificates, to November 29, 2024, 152 days after the last day of the quarter ended June 30, 2024.
On September 18, 2024, the Company received a notice of default relating to its 6.750% Senior Notes due 2027 because the Company failed to timely furnish a Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2024. The Company has 90 days from receipt of the notice to remedy prior to it becoming an Event of Default under the terms of the Indenture, dated November 29, 2019.
v3.24.3
Commitments and Contingencies
9 Months Ended
Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies Commitments and Contingencies:
As previously disclosed, the Company was the subject of an investigation by the Division of Enforcement of the SEC regarding the Company’s disclosures primarily concerning the operation of the Goderich mine, the former South American businesses, and related accounting and internal control matters including Salt interim inventory valuation methodology issues that were disclosed in the Company’s Form 10-K/A for the year ended December 31, 2020, and Form 10-Q/A for the quarter ended March 31, 2021, each filed with the SEC on September 3, 2021.

On September 23, 2022, the Company reached a settlement with the SEC, concluding and resolving the SEC investigation in its entirety. Under the terms of the settlement, the Company, without admitting or denying the findings in the administrative order issued by the SEC, agreed to pay a civil penalty of $12 million and to cease and desist from violations of specified provisions of the federal securities laws and rules promulgated thereunder, and to retain an independent compliance consultant for a period of approximately one year to review certain accounting practices and procedures. As set forth in the administrative order, the $12 million civil penalty was paid in installments with $10 million reflected in accrued expenses and other current liabilities on the Company’s Consolidated Balance Sheets as of September 30, 2023 and subsequently paid in during the first quarter of fiscal 2024.

On April 24, 2024, the Company, two of its former officers and two current officers were named as defendants in a putative securities class action lawsuit filed in the United States District Court for the District of Kansas, alleging that the Company and such officers made misleading statements damaging shareholders relating to the Company’s fire retardant business. The Company intends to vigorously defend these allegations. At this time, the Company is unable to assess with any certainty what, if any, damages could be awarded in this matter.
On May 1, 2024, Fortress was named as defendant in a trade secrets lawsuit filed by Perimeter Solutions L.P. in the United States District Court for the Eastern District of California, alleging that certain of Fortress’s non-magnesium chloride fire retardant products were developed using Perimeter’s trade secrets, and seeking unspecified damages (including exemplary damages) and injunctive relief. The Company intends to vigorously defend these allegations. At this time, the Company is unable to assess with any certainty what, if any, damages could be awarded in this matter. On May 1, 2024, Perimeter Solutions L.P. also filed a lawsuit in the United States District Court for the Eastern District of Missouri alleging similar claims against an employee of Fortress for breach of contract and misappropriation of trade secrets. On September 6, 2024, the Eastern District of Missouri dismissed without prejudice the suit filed against the Fortress employee.

The Company is also involved in legal and administrative proceedings and claims of various types from the ordinary course of the Company’s business.

Management cannot predict the outcome of legal claims and proceedings with certainty. Nevertheless, management believes that the outcome of legal proceedings and claims, which are pending or known to be threatened, even if determined adversely, will not, individually or in the aggregate, have a material adverse effect on the Company’s results of operations, cash flows or financial position, except as otherwise described in Note 7 and this Note 9.
v3.24.3
Operating Segments
9 Months Ended
Jun. 30, 2024
Segment Reporting [Abstract]  
Operating Segments Operating Segments:
 
The Company’s reportable segments are strategic business units that offer different products and services, and each business requires different technology and marketing strategies. For the three and nine months ended June 30, 2024 and 2023, the Company has presented two reportable segments in its Consolidated Financial Statements: Salt and Plant Nutrition. The Salt segment produces and markets salt, consisting of sodium chloride and magnesium chloride, for use in road deicing for winter roadway safety and for dust control, food processing, water softening and other consumer, agricultural and industrial applications. The Plant Nutrition segment produces and markets various grades of SOP. The results of operations for the Company’s fire retardant and records management businesses are included in Corporate and Other in the tables below. Refer to Note 2 for a discussion of the acquisition of the fire retardant business.

Segment information is as follows (in millions):
Three Months Ended June 30, 2024SaltPlant
Nutrition
Corporate
& Other(a)
Total
Sales to external customers$160.6 $38.8 $3.5 $202.9 
Intersegment sales— 2.8 (2.8)— 
Shipping and handling cost48.2 5.0 — 53.2 
Operating earnings (loss)(c)(d)
25.9 (1.4)(18.6)5.9 
Depreciation, depletion and amortization15.7 8.6 1.8 26.1 
Total assets (as of end of period)1,013.3 408.1 173.8 1,595.2 

Three Months Ended June 30, 2023SaltPlant
Nutrition
Corporate
& Other(a)
Total
Sales to external customers$155.5 $47.5 $4.6 $207.6 
Intersegment sales— 2.8 (2.8)— 
Shipping and handling cost48.2 5.6 — 53.8 
Operating earnings (loss)(d)
21.7 2.5 (24.8)(0.6)
Depreciation, depletion and amortization14.2 8.2 1.9 24.3 
Total assets (as of end of period)970.1 477.1 286.3 1,733.5 
Nine Months Ended June 30, 2024SaltPlant
Nutrition
Corporate
& Other(a)
Total
Sales to external customers$745.3 $138.6 $24.7 $908.6 
Intersegment sales— 6.6 (6.6)— 
Shipping and handling cost235.9 18.6 0.6 255.1 
Operating earnings (loss)(b)(c)(d)
142.6 (56.7)(172.9)(87.0)
Depreciation, depletion and amortization47.1 25.7 5.6 78.4 

Nine Months Ended June 30, 2023SaltPlant
Nutrition
Corporate
& Other(a)
Total
Sales to external customers$824.1 $136.8 $10.2 $971.1 
Intersegment sales— 7.1 (7.1)— 
Shipping and handling cost274.9 16.4 — 291.3 
Operating earnings (loss)(c)(d)
141.9 12.8 (79.5)75.2 
Depreciation, depletion and amortization42.9 24.6 5.2 72.7 

Disaggregated revenue by product type is as follows (in millions):
Three Months Ended June 30, 2024SaltPlant
Nutrition
Corporate
& Other(a)
Total
Highway Deicing Salt$84.1 $— $— $84.1 
Consumer & Industrial Salt76.5 — — 76.5 
SOP— 41.6 — 41.6 
Eliminations & Other— (2.8)3.5 0.7 
Sales to external customers$160.6 $38.8 $3.5 $202.9 

Three Months Ended June 30, 2023SaltPlant
Nutrition
Corporate
& Other(a)
Total
Highway Deicing Salt$79.0 $— $— $79.0 
Consumer & Industrial Salt76.5 — — 76.5 
SOP— 50.3 — 50.3 
Fire Retardant— — 1.9 1.9 
Eliminations & Other— (2.8)2.7 (0.1)
Sales to external customers$155.5 $47.5 $4.6 $207.6 

Nine Months Ended June 30, 2024SaltPlant
Nutrition
Corporate
& Other(a)
Total
Highway Deicing Salt$471.1 $— $— $471.1 
Consumer & Industrial Salt274.2 — — 274.2 
SOP— 145.2 — 145.2 
Fire Retardant— — 14.1 14.1 
Revenue from Services— — 0.5 0.5 
Eliminations & Other— (6.6)10.1 3.5 
Sales to external customers$745.3 $138.6 $24.7 $908.6 
Nine Months Ended June 30, 2023SaltPlant
Nutrition
Corporate
& Other(a)
Total
Highway Deicing Salt$543.0 $— $— $543.0 
Consumer & Industrial Salt281.1 — — 281.1 
SOP— 143.9 — 143.9 
Fire Retardant— — 1.9 1.9 
Eliminations & Other— (7.1)8.3 1.2 
Sales to external customers$824.1 $136.8 $10.2 $971.1 
(a)Corporate and Other includes corporate entities, records management operations, the Fortress fire retardant business, equity method investments, lithium costs and other incidental operations and eliminations. Operating earnings (loss) for corporate and other includes indirect corporate overhead, including costs for general corporate governance and oversight, lithium-related expenses, as well as costs for the human resources, information technology, legal and finance functions.
(b)The Company recognized impairments of $175.8 million for the nine months ended June 30, 2024, which impacted operating results. Refer to Note 1 for additional information regarding the Plant Nutrition and Fortress impairments and Note 5 for additional information about the impairment of lithium development assets.
(c)Corporate operating results were impacted by net gains of $0.9 million and $23.1 million related to the decline in the valuation of the Fortress contingent consideration for the three and nine months ended June 30, 2024, respectively. Corporate operating results also include net reimbursements related to the settled SEC investigation of $0.1 million for the nine months ended June 30, 2023. Refer to Note 9 for more information regarding the SEC investigation and settlement and Note 13 for information regarding the Fortress contingent consideration.
(d)The Company continued to take steps to align its cost structure to its current business needs. These initiatives impacted Corporate operating results and resulted in net severance and related charges for reductions in workforce and changes to executive leadership and additional restructuring costs related to the termination of the Company’s lithium development project of $1.5 million and $17.2 million for the three and nine months ended June 30, 2024, respectively, and $2.2 million and $5.5 million for the three and nine months ended June 30, 2023, respectively.

The Company’s revenue by geographic area is as follows (in millions):
Three Months Ended
June 30,
Nine Months Ended
June 30,
Revenue2024202320242023
United States(a)
$158.4 $164.4 $679.4 $695.7 
Canada35.7 35.9 191.4 224.5 
United Kingdom7.9 6.6 35.0 43.9 
Other0.9 0.7 2.8 7.0 
Total revenue$202.9 $207.6 $908.6 $971.1 
(a)United States sales exclude product sold to foreign customers at U.S. ports.
v3.24.3
Stockholders' Equity and Equity Instruments
9 Months Ended
Jun. 30, 2024
Equity [Abstract]  
Stockholders' Equity and Equity Instruments Stockholders’ Equity and Equity Instruments:
Equity Compensation Awards

In May 2020, the Company’s stockholders approved the 2020 Incentive Award Plan (as amended, the “2020 Plan”), which authorized the issuance of 2,977,933 shares of Company common stock. In February 2022, the Company’s stockholders approved an amendment to the 2020 Plan authorizing an additional 750,000 shares of Company stock. In March 2024, the Company’s stockholders approved an amendment to the 2020 Plan authorizing an additional 3,000,000 shares of Company stock. Since the date the 2020 Plan was approved, the Company ceased issuing equity awards under the 2015 Incentive Award Plan (as amended, the “2015 Plan”). Since the approval of the 2015 Plan in May 2015, the Company ceased issuing equity awards under the 2005 Incentive Award Plan (as amended, the “2005 Plan”). The 2005 Plan, the 2015 Plan and the 2020 Plan allow for grants of equity awards to executive officers, other employees and directors, including restricted stock units (“RSUs”), performance stock units (“PSUs”), stock options and deferred stock units. For additional information regarding equity awards issued under the Company’s incentive plans refer to “Note 16 – Stockholder’s Equity and Equity Instruments” within Part II, Item 8 of its 2023 Form 10-K/A.

During the nine months ended June 30, 2024, the Company reissued the following number of shares from treasury stock: 252,798 shares related to the release of RSUs which vested and 46,039 shares issued for Board of Director compensation. In fiscal 2023, the Company issued 158,132 net shares from treasury stock. The Company withheld a total of 96,088 shares with a fair value of $2.1 million related to the vesting of RSUs during the nine months ended June 30, 2024. The fair value of the
shares was valued at the closing price at the vesting date and represent the employee tax withholding for the employee’s compensation. The Company recognized tax expense of $1.0 million from its equity compensation awards during the nine months ended June 30, 2024. During the nine months ended June 30, 2024 and 2023, the Company recorded $8.1 million and $17.7 million (includes $1.8 million and $0.5 million paid in cash), respectively, of compensation expense pursuant to its stock-based compensation plans. No amounts have been capitalized.

PSUs

During the nine months ended June 30, 2024, the Company issued new PSUs based upon several operational performance measures (“Scorecard PSUs”). The actual number of shares of common stock that may be earned with respect to Scorecard PSUs is calculated based upon the attainment of free cash flow, cash unit costs, cash unit cost reduction, capital expenditures and safety measures during the performance period and may range from 0% to 300% for each measure.

The following table summarizes stock-based compensation activity during the nine months ended June 30, 2024:
 Stock OptionsRSUs
PSUs(a)
 NumberWeighted-average
exercise price
NumberWeighted-average
fair value
NumberWeighted-average
fair value
Outstanding at September 30, 2023
642,995 $59.46 393,240 $42.50 393,579 $71.37 
Granted— — 533,399 25.55 276,916 24.69 
Exercised(b)
— — — — — — 
Released from restriction(b)
— — (252,798)40.18 — — 
Cancelled/expired(443,227)57.97 (202,439)32.54 (425,561)56.85 
Outstanding at June 30, 2024
199,768 $62.78 471,402 $28.84 244,934 $43.88 
(a)Until the performance period is completed, PSUs are included in the table at the target level at their grant date and at that level represent one share of common stock per PSU.
(b)Common stock issued for exercised options and for vested and earned RSUs and PSUs was issued from treasury stock.

Accumulated Other Comprehensive Loss (“AOCL”)

The Company’s comprehensive income (loss) is comprised of net loss, net amortization of the unrealized loss of the pension obligation, the change in the unrealized gain in other postretirement benefits, the change in the unrealized gain (loss) on natural gas and foreign currency cash flow hedges and currency translation adjustment (“CTA”). The components of and changes in AOCL are as follows (in millions):
Three Months Ended June 30, 2024(a)
Gains and (Losses) on Cash Flow HedgesDefined Benefit PensionOther Post-Employment BenefitsForeign CurrencyTotal
Beginning balance$(2.6)$(6.2)$1.7 $(96.5)$(103.6)
Other comprehensive loss before reclassifications(b)
(0.6)— — (4.9)(5.5)
Amounts reclassified from AOCL1.5 0.3 (0.1)— 1.7 
Net current period other comprehensive income (loss)
0.9 0.3 (0.1)(4.9)(3.8)
Ending balance$(1.7)$(5.9)$1.6 $(101.4)$(107.4)

Three Months Ended June 30, 2023(a)
Gains and (Losses) on Cash Flow Hedges
Defined Benefit PensionOther Post-Employment BenefitsForeign CurrencyTotal
Beginning balance$(5.5)$(2.6)$1.3 $(97.8)$(104.6)
Other comprehensive income before reclassifications(b)
0.4 — — 11.8 12.2 
Amounts reclassified from AOCL1.8 — — — 1.8 
Net current period other comprehensive income
2.2 — — 11.8 14.0 
Ending balance$(3.3)$(2.6)$1.3 $(86.0)$(90.6)
Nine Months Ended June 30, 2024(a)
Gains and (Losses) on Cash Flow HedgesDefined Benefit PensionOther Post-Employment BenefitsForeign CurrencyTotal
Beginning balance$(1.4)$(6.6)$1.7 $(98.4)$(104.7)
Other comprehensive loss before reclassifications(b)
(3.4)— — (3.0)(6.4)
Amounts reclassified from AOCL3.1 0.7 (0.1)— 3.7 
Net current period other comprehensive (loss) income(0.3)0.7 (0.1)(3.0)(2.7)
Ending balance$(1.7)$(5.9)$1.6 $(101.4)$(107.4)

Nine Months Ended June 30, 2023(a)
Gains and (Losses) on Cash Flow HedgesDefined Benefit PensionOther Post-Employment BenefitsForeign CurrencyTotal
Beginning balance$(1.6)$(2.7)$1.3 $(112.3)$(115.3)
Other comprehensive (loss) income before reclassifications(b)
(3.8)— — 26.3 22.5 
Amounts reclassified from AOCL2.1 0.1 — — 2.2 
Net current period other comprehensive (loss) income(1.7)0.1 — 26.3 24.7 
Ending balance$(3.3)$(2.6)$1.3 $(86.0)$(90.6)
(a)With the exception of the CTA, for which no tax effect is recorded, the changes in the components of AOCL presented in the tables above are reflected net of applicable income taxes.
(b)The Company recorded foreign exchange gain (loss) of $1.0 million and $1.0 million in the three and nine months ended June 30, 2024, respectively, and $(2.0) million and $(3.4) million in the three and nine months ended June 30, 2023, respectively, in AOCL related to intercompany notes which were deemed to be of a long-term investment nature.

The amounts reclassified from AOCL to expense (income) for the three and nine months ended June 30, 2024 and 2023, are shown below (in millions):
Amount Reclassified from AOCL
 Three Months Ended
June 30,
Nine Months Ended
June 30,
Line Item Impacted in the
Consolidated Statements of Operations
2024202320242023
Loss (gain) on cash flow hedges:
Natural gas instruments$1.5 $2.4 $3.1 $2.9 Product cost
Income tax expense— (0.6)— (0.8)
Reclassifications, net of income taxes1.5 1.8 3.1 2.1 
Amortization of defined benefit pension: 
Amortization of loss0.3 — 0.9 0.1 Product cost
Income tax benefit— — (0.2)— 
Reclassifications, net of income taxes0.3 — 0.7 0.1  
Amortization of other post-employment benefits:
Amortization of gain(0.1)— (0.1)— Product cost
Income tax expense— — — — 
Reclassifications, net of income taxes(0.1)— (0.1)— 
Total reclassifications, net of income taxes$1.7 $1.8 $3.7 $2.2  
v3.24.3
Derivative Financial Instruments
9 Months Ended
Jun. 30, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Derivative Financial Instruments Derivative Financial Instruments:
 
The Company is subject to various types of market risks, including interest rate risk, foreign currency exchange rate transaction and translation risk and commodity pricing risk. Management may take actions to mitigate the exposure to these types of risks, including entering into forward purchase contracts and other financial instruments. The Company manages a portion of its commodity pricing risks and foreign currency exchange rate risks by using derivative instruments. From time to time, the Company may enter into foreign exchange contracts to mitigate foreign exchange risk. The Company does not seek to engage in trading activities or take speculative positions with any financial instrument arrangement. The Company enters into natural gas derivative instruments and foreign currency derivative instruments with counterparties it views as creditworthy. However, the Company does attempt to mitigate its counterparty credit risk exposures by, among other things, entering into master netting agreements with some of these counterparties. The Company records derivative financial instruments as either assets or liabilities at fair value in its Consolidated Balance Sheets. The assets and liabilities recorded as of June 30, 2024 and September 30, 2023 were not material.

Derivatives qualify for treatment as hedges when there is a high correlation between the change in fair value of the derivative instrument and the related change in value of the underlying hedged item. Depending on the exposure being hedged, the Company must designate the hedging instrument as a fair value hedge, a cash flow hedge or a net investment in foreign operations hedge. For the qualifying derivative instruments that have been designated as cash flow hedges, the effective portion of the change in fair value is recognized through earnings when the underlying transaction being hedged affects earnings, allowing a derivative’s gains and losses to offset related results from the hedged item in the Consolidated Statements of Operations. Any ineffectiveness related to these instruments accounted for as hedges was not material for any of the periods presented. For derivative instruments that have not been designated as hedges, the entire change in fair value is recorded through earnings in the period of change.

Natural Gas Derivative Instruments

Natural gas is consumed at several of the Company’s production facilities, and changes in natural gas prices impact the Company’s operating margin. The Company seeks to reduce the earnings and cash flow impacts of changes in market prices of natural gas by fixing the purchase price of up to 90% of its forecasted natural gas usage. It is the Company’s policy to consider hedging portions of its natural gas usage up to 36 months in advance of the forecasted purchase. As of June 30, 2024, the Company had entered into natural gas derivative instruments to hedge a portion of its natural gas purchase requirements through December 2025. As of June 30, 2024 and September 30, 2023, the Company had agreements in place to hedge forecasted natural gas purchases of 2.9 million and 2.3 million MMBtus, respectively.

On March 1, 2023, the Company de-designated its natural gas cash flow hedges related to its Ogden, Utah production facility as the Company did not believe these hedges were probable of being highly effective in the second fiscal quarter of 2023. Beginning March 1, 2023, the change in the derivative was and will be recorded in other expense, net in the Consolidated Statements of Operations. Since the transactions are still probable of occurring, previously recognized amounts in AOCL of $0.1 million remain in AOCL until the underlying forecasted transaction occurs. The Company recognized $0.1 million and $0.8 million of expense in other expense, net on the Consolidated Statements of Operations during the three and nine months ended June 30, 2024, respectively. Following the de-designation, these natural gas economic hedging instruments will be recorded at fair value through earnings unless re-designated or until settlement. Substantially all other natural gas derivative instruments held by the Company as of June 30, 2024 and September 30, 2023 qualified and were designated as cash flow hedges. As of June 30, 2024, the Company expects to reclassify from AOCL to earnings during the next twelve months $1.5 million of net losses on derivative instruments related to its natural gas hedges. Refer to Note 13 for the estimated fair value of the Company’s natural gas derivative instruments as of June 30, 2024 and September 30, 2023.
The following tables present the fair value of the Company’s derivatives (in millions):
 Asset DerivativesLiability Derivatives
Consolidated Balance Sheet LocationJune 30, 2024Consolidated Balance Sheet LocationJune 30, 2024
Derivatives designated as hedging instruments:
Commodity contractsOther current assets$0.9 Accrued expenses and other current liabilities$2.4 
Commodity contractsOther assets0.2 Other noncurrent liabilities0.4 
Total derivatives designated as hedging instruments1.1 2.8 
Derivatives not designated as hedging instruments:
Commodity contractsOther current assets— Accrued expenses and other current liabilities0.1 
Total derivatives not designated as hedging instruments— 0.1 
Total derivatives(a)
$1.1 $2.9 
(a)The Company has master netting agreements with its commodity hedge counterparties and accordingly has netted in its Consolidated Balance Sheets $1.1 million of its commodity contracts that are in receivable positions against its contracts in payable positions.

 Asset DerivativesLiability Derivatives
Consolidated Balance Sheet LocationSeptember 30, 2023Consolidated Balance Sheet LocationSeptember 30, 2023
Derivatives designated as hedging instruments:
Commodity contractsOther current assets$0.9 Accrued expenses and other current liabilities$2.3 
Total derivatives designated as hedging instruments0.9 2.3 
Derivatives not designated as hedging instruments:
Commodity contractsOther current assets0.1 Accrued expenses and other current liabilities— 
Total derivatives not designated as hedging instruments0.1 — 
Total derivatives(a)
$1.0 $2.3 
(a)The Company has master netting agreements with its commodity hedge counterparties and accordingly has netted in its Consolidated Balance Sheets $1.0 million of its commodity contracts that are in receivable positions against its contracts in payable positions.
v3.24.3
Fair Value Measurements
9 Months Ended
Jun. 30, 2024
Fair Value Disclosures [Abstract]  
Fair Value Measurements Fair Value Measurements:
The Company’s financial instruments are measured and reported at their estimated fair values. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction. When available, the Company uses quoted prices in active markets to determine the fair values for its financial instruments (Level 1 inputs) or, absent quoted market prices, observable market-corroborated inputs over the term of the financial instruments (Level 2 inputs). The Company does not have any unobservable inputs that are not corroborated by market inputs (Level 3 inputs), except as stated below and in Note 2.
 
The Company holds marketable securities associated with its defined contribution and pre-tax savings plans, which are valued based on readily available quoted market prices. The Company utilizes derivative instruments to manage its risk of changes in natural gas prices and foreign exchange rates (see Note 12). The fair values of the natural gas and foreign currency derivative instruments are determined using market data of forward prices for all of the Company’s contracts. 
The estimated fair values for each type of instrument are presented below (in millions):
 June 30,
2024
Level OneLevel TwoLevel Three
Asset Class:
Mutual fund investments in a non-qualified savings plan(a)
$3.1 $3.1 $— $— 
Total Assets$3.1 $3.1 $— $— 
Liability Class:    
Derivatives designated as hedging instruments - natural gas instruments, net$(1.7)$— $(1.7)$— 
Derivatives not designated as hedging instruments - natural gas instruments, net(0.1)— (0.1)— 
Liabilities related to non-qualified savings plan(3.1)(3.1)— — 
Total Liabilities$(4.9)$(3.1)$(1.8)$— 
(a)Includes mutual fund investments of approximately 30% in common stock of large-cap U.S. companies, 5% in common stock of small to mid-cap U.S. companies, 5% in international companies, 15% in bond funds, 5% in short-term investments and 40% in blended funds.

 September 30,
2023
 
Level One
 
Level Two
 
Level Three
Asset Class:
Mutual fund investments in a non-qualified savings plan(a)
$2.6 $2.6 $— $— 
Derivatives not designated as hedging instruments - natural gas instruments, net0.1 — 0.1 — 
Total Assets$2.7 $2.6 $0.1 $— 
Liability Class:    
Derivatives designated as hedging instruments - natural gas instruments, net$(1.4)$— $(1.4)$— 
Liabilities related to non-qualified savings plan(2.6)(2.6)— — 
Total Liabilities$(4.0)$(2.6)$(1.4)$— 
(a)Includes mutual fund investments of approximately 25% in the common stock of large-cap U.S. companies, 5% in the common stock of small to mid-cap U.S. companies, 10% in the common stock of international companies, 10% in bond funds, 5% in short-term investments and 45% in blended funds.

Cash and cash equivalents, receivables (net of allowance for doubtful accounts) and accounts payable are carried at cost, which approximates fair value due to their liquid and short-term nature. The Company’s investments related to its non-qualified retirement plan of $3.1 million at June 30, 2024 and $2.6 million at September 30, 2023, are stated at fair value based on quoted market prices. As of June 30, 2024 and September 30, 2023, the estimated fair value of the Company’s fixed-rate 6.75% Senior Notes due December 2027, based on available trading information (Level 2), totaled $477.5 million and $472.5 million, respectively, compared with the aggregate principal amount at maturity of $500.0 million. The fair value at June 30, 2024 and September 30, 2023 of amounts outstanding under the Company’s term loans and revolving credit facility, based upon available bid information received from the Company’s lender (Level 2), totaled approximately $342.7 million and $277.1 million, respectively, compared with the aggregate principal amount at maturity of $346.9 million and $280.3 million, respectively.

In connection with the acquisition of Fortress, the Company entered into a contingent consideration arrangement (milestone and earnout payments). The fair value of the milestone contingent consideration is estimated using a probability-weighted discounted cash flow model with significant inputs not observable in the market and is therefore considered a Level 3 measurement while the earn-out is valued using a Monte Carlo simulation, also a Level 3 measurement. For the three and nine months ended June 30, 2024, the Company recorded income of $0.9 million and $23.1 million, respectively. The change in the three months ended June 30, 2024 is reflective of updated financial performance, changes in discount rates and the passage of time. The change in the nine months ended June 30, 2024 is also reflective of milestone and earn-out payments made related to calendar year 2023 activity and recent developments related to the Company’s magnesium chloride-based fire retardants, as discussed further in Note 1. The change is recorded in other operating (income) expense in the Consolidated Statements of Operations to reflect the contingent consideration liability at its fair value as of June 30, 2024. The Company will continue to recognize remeasurement changes in the estimated fair value of contingent consideration in earnings at each reporting date until all contingencies are resolved. Refer to Note 2 for a discussion of the milestone and earnout payments.
The following table presents the fair value of the Company’s total contingent consideration arrangement (in millions):
Consolidated Balance Sheet LocationJune 30, 2024September 30, 2023
Accrued expenses and other current liabilities$— $7.3 
Other noncurrent liabilities6.9 31.8 
Total contingent consideration(a)
$6.9 $39.1 
(a)The decrease in total contingent consideration was related to a net $23.1 million decrease in the fair value of the remaining contingent consideration, discussed further above, and $9.1 million of payments made during the nine months ended June 30, 2024.

The Company has certain assets, including goodwill and other intangible assets, which are measured at fair value on a non-recurring basis and are adjusted to fair value only if an impairment charge is recognized. The categorization of the framework used to measure fair value of the assets is considered to be within the Level 3 valuation hierarchy due to the subjective nature of the unobservable inputs used. Refer to Note 1 for details of the Company’s impairment of goodwill related to Plant Nutrition and Fortress, Note 5 for details of the Company’s impairment of long-lived assets related the termination of its lithium development and Note 6 for details of the Company’s intangible asset impairment related to Fortress.
v3.24.3
Earnings per Share
9 Months Ended
Jun. 30, 2024
Earnings Per Share [Abstract]  
Earnings per Share Earnings per Share:
 
On April 22, 2024, the Board of Directors determined not to declare dividends for the foreseeable future in order to align the Company’s capital allocation priorities with its corporate focus on accelerating cash flow generation and debt reduction. The Company calculated earnings per share using the treasury stock method during the three months ended June 30, 2024. The following table sets forth the computation of basic and diluted earnings per common share (in millions, except for share and per-share data):
 Three Months Ended
June 30,
Nine Months Ended
June 30,
 2024202320242023
Numerator:
Net (loss) earnings$(43.6)$36.4 $(157.8)$14.5 
Less: net earnings allocated to participating securities(a)
— (0.4)(0.2)(0.2)
Net (loss) earnings available to common stockholders$(43.6)$36.0 $(158.0)$14.3 
Denominator (in thousands):
Weighted-average common shares outstanding, shares for basic earnings per share41,342 41,142 41,284 40,663 
Weighted-average awards outstanding(b)
— — — — 
Shares for diluted earnings per share41,342 41,142 41,284 40,663 
Basic net (loss) earnings per common share$(1.05)$0.88 $(3.83)$0.35 
Diluted net (loss) earnings per common share$(1.05)$0.88 $(3.83)$0.35 
(a)Weighted participating securities include RSUs and PSUs that receive non-forfeitable dividends and consist of 632,000 and 698,000 weighted participating securities for the three and nine months ended June 30, 2024, respectively, and 453,000 and 469,000 weighted participating securities for the three and nine months ended June 30, 2023, respectively.
(b)For the calculation of diluted net earnings (loss) per share, the Company uses the more dilutive of either the treasury stock method or the two-class method to determine the weighted-average number of outstanding common shares. In addition, the Company had 874,000 and 1,427,000 weighted-average equity awards outstanding for the three and nine months ended June 30, 2024, respectively, and 1,151,000 and 1,267,000 weighted-average equity awards outstanding for the three and nine months ended June 30, 2023, respectively, that were anti-dilutive.
v3.24.3
Related Party Transactions
9 Months Ended
Jun. 30, 2024
Related Party Transactions [Abstract]  
Related Party Transactions Related Party Transactions:
During both the three and nine months ended June 30, 2024 and 2023, the Company recorded SOP sales of approximately $0.9 million and $2.7 million, respectively, to certain subsidiaries of Koch Industries, Inc. As of June 30, 2024 and September 30, 2023, the Company had approximately $0.5 million and $0.4 million, respectively, of receivables from related parties on its Consolidated Balance Sheets. There were no amounts payable outstanding as of June 30, 2024.
On December 20, 2023 and March 20, 2024, the Company paid a cash dividend to its stockholders of record at the close of business on December 11, 2023 and March 11, 2024, respectively, in the amount of $0.15 per share. Koch Minerals & Trading, LLC received approximately $2.1 million in respect to its common shares for the nine months ended June 30, 2024.
v3.24.3
Subsequent Events
9 Months Ended
Jun. 30, 2024
Subsequent Events [Abstract]  
Subsequent Events Subsequent Events:
On September 3, 2024, the Company announced a binding Voluntary Agreement (“Agreement”) with the Utah Division of Forestry, Fire and State Lands (“FFSL”) outlining water and land conservation commitments the company is making toward the long-term health of the Great Salt Lake. Per the terms of the Agreement, the Company will donate non-production-related water rights totaling approximately 201,000 acre feet annually to be used by the State of Utah for lake conservation and preservation. In connection with the donation of water rights, the Company performed a fair value analysis of the indefinite-lived intangible asset that resulted in an impairment of approximately $17.6 million.
Additionally, the Company will remit back to the State of Utah nearly 65,000 acres of leasehold, also currently not utilized for production, which will subsequently be set aside from future mineral leasing to be preserved in perpetuity for conservation and other beneficial uses according to FFSL’s existing management authority. Finally, the Agreement outlines a progressive set of brine withdrawal caps for certain of the Company’s consumptive water rights, based on annual lake elevation and informed by the Great Salt Lake Strategic Plan. The Company does not expect these consumption caps to materially impact its essential mineral production on the Great Salt Lake unless lake elevations were to fall to historic lows.
v3.24.3
Pay vs Performance Disclosure - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Pay vs Performance Disclosure        
Net Income (Loss) $ (43.6) $ 36.4 $ (157.8) $ 14.5
v3.24.3
Insider Trading Arrangements
3 Months Ended
Jun. 30, 2024
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
v3.24.3
Accounting Policies and Basis of Presentation (Policies)
9 Months Ended
Jun. 30, 2024
Accounting Policies [Abstract]  
Basis of Consolidation
CMI is a holding company with no significant operations other than those of its wholly-owned subsidiaries. The consolidated financial statements include the accounts of CMI and its wholly-owned domestic and foreign subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
Basis of Presentation
The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete consolidated financial statements. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements of the Company for the annual period ended September 30, 2023, as filed with the Securities and Exchange Commission (the “SEC”) in its Amended Annual Report on Form 10-K/A on October 29, 2024 (“2023 Form 10-K/A”). Certain amounts in prior periods have been reclassified to conform to the current period presentation. In the opinion of management, all adjustments, consisting of normal recurring adjustments considered necessary for a fair presentation, have been included.
Recent Accounting Pronouncements
Recent Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures”, which updates reportable segment disclosure requirements primarily to include enhanced disclosures about significant segment expenses. The amendments are effective for fiscal years beginning after December 15, 2023, and for interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. The amendments should be applied retrospectively to all prior periods presented in the financial statements. Management is currently evaluating this ASU to determine its impact on the Company's disclosures.

In December 2023, the FASB issued ASU 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures”, which updates income tax disclosures by requiring consistent categories and additional disaggregation of information in the rate reconciliation and income taxes paid by jurisdiction. The amendments are effective for fiscal years beginning after December 15, 2024. Early adoption is permitted. The amendments should be applied prospectively; however, retrospective application is permitted. Management is currently evaluating this ASU to determine its impact on the Company’s disclosures.
Revenues
Deferred Revenue
Deferred revenue represents billings under non-cancellable contracts before the related product or service is transferred to the customer. The portion of deferred revenue that is anticipated to be recognized as revenue during the succeeding twelve-month period is recorded in accrued expenses and other current liabilities on the Consolidated Balance Sheets.
Derivative Financial Instruments
The Company is subject to various types of market risks, including interest rate risk, foreign currency exchange rate transaction and translation risk and commodity pricing risk. Management may take actions to mitigate the exposure to these types of risks, including entering into forward purchase contracts and other financial instruments. The Company manages a portion of its commodity pricing risks and foreign currency exchange rate risks by using derivative instruments. From time to time, the Company may enter into foreign exchange contracts to mitigate foreign exchange risk. The Company does not seek to engage in trading activities or take speculative positions with any financial instrument arrangement. The Company enters into natural gas derivative instruments and foreign currency derivative instruments with counterparties it views as creditworthy. However, the Company does attempt to mitigate its counterparty credit risk exposures by, among other things, entering into master netting agreements with some of these counterparties. The Company records derivative financial instruments as either assets or liabilities at fair value in its Consolidated Balance Sheets. The assets and liabilities recorded as of June 30, 2024 and September 30, 2023 were not material.
Derivatives qualify for treatment as hedges when there is a high correlation between the change in fair value of the derivative instrument and the related change in value of the underlying hedged item. Depending on the exposure being hedged, the Company must designate the hedging instrument as a fair value hedge, a cash flow hedge or a net investment in foreign operations hedge. For the qualifying derivative instruments that have been designated as cash flow hedges, the effective portion of the change in fair value is recognized through earnings when the underlying transaction being hedged affects earnings, allowing a derivative’s gains and losses to offset related results from the hedged item in the Consolidated Statements of Operations. Any ineffectiveness related to these instruments accounted for as hedges was not material for any of the periods presented. For derivative instruments that have not been designated as hedges, the entire change in fair value is recorded through earnings in the period of change.
v3.24.3
Accounting Policies and Basis of Presentation (Tables)
9 Months Ended
Jun. 30, 2024
Accounting Policies [Abstract]  
Schedule of Impairments Incurred A summary of the impairments incurred for the nine months ended June 30, 2024, is detailed below (in millions):
Impairment
Financial Statement Line Item
Segment
Nine Months Ended
June 30, 2024
Lithium long-lived assets, net
Loss on impairments
Corporate & Other
$74.8 
Plant Nutrition goodwill
Loss on impairments
Plant Nutrition
51.0 
Fortress goodwill
Loss on impairments
Corporate & Other32.0 
Fortress long-lived assets, net
Loss on impairments
Corporate & Other15.6 
Fortress inventory
Product cost
Corporate & Other2.4 
Total
$175.8 
v3.24.3
Inventories (Tables)
9 Months Ended
Jun. 30, 2024
Inventory Disclosure [Abstract]  
Schedule of Inventories
Inventories consist of the following (in millions):
 June 30,
2024
September 30,
2023
Finished goods$315.3 $319.3 
Work in process
7.3 7.3 
Raw materials and supplies(a)
84.9 72.9 
Total inventories
$407.5 $399.5 
(a)Excludes certain raw materials and supplies of $35.6 million and $35.8 million as of June 30, 2024 and September 30, 2023, respectively, that are not expected to be consumed within the next twelve months, included in Other noncurrent assets in the Consolidated Balance Sheets.
v3.24.3
Property, Plant and Equipment, Net (Tables)
9 Months Ended
Jun. 30, 2024
Property, Plant and Equipment [Abstract]  
Schedule of Property, Plant and Equipment, Net
Property, plant and equipment, net, consists of the following (in millions):
 June 30,
2024
September 30,
2023
Land, buildings and structures, and leasehold improvements$552.6 $547.9 
Machinery and equipment1,127.9 1,102.0 
Office furniture and equipment22.4 21.6 
Mineral interests169.2 169.1 
Construction in progress68.0 113.3 
 1,940.1 1,953.9 
Less: accumulated depreciation and depletion(1,152.2)(1,101.4)
Property, plant and equipment, net$787.9 $852.5 
v3.24.3
Goodwill and Intangible Assets (Tables)
9 Months Ended
Jun. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule of Changes in the Carrying Amount of Goodwill
Changes in the carrying amount of goodwill are summarized as follows (in millions):
Plant Nutrition
Corporate & Other
Consolidated
Balance as of September 30, 2023$51.1 $37.7 $88.8 
Foreign currency translation adjustment0.2 0.2 0.4 
Balance as of December 31, 202351.3 37.9 89.2 
Foreign currency translation adjustment(0.3)— (0.3)
Impairments(51.0)(32.0)(83.0)
Balance as of March 31, 2024— 5.9 5.9 
Foreign currency translation adjustment— — — 
Balance as of June 30, 2024
$— $5.9 $5.9 
v3.24.3
Long-Term Debt (Tables)
9 Months Ended
Jun. 30, 2024
Debt Disclosure [Abstract]  
Schedule of Long-Term Debt
Long-term debt consists of the following (in millions):
 June 30,
2024
September 30,
2023
6.75% Senior Notes due December 2027
$500.0 $500.0 
Term Loan due May 2028195.0 198.8 
Revolving Credit Facility due May 2028151.9 81.5 
AR Securitization Facility expires March 202733.8 30.9 
880.7 811.2 
Less unamortized debt issuance costs(5.6)(5.9)
Total debt875.1 805.3 
Less current portion(6.3)(5.0)
Long-term debt$868.8 $800.3 
v3.24.3
Operating Segments (Tables)
9 Months Ended
Jun. 30, 2024
Segment Reporting [Abstract]  
Schedule of Segment Information
Segment information is as follows (in millions):
Three Months Ended June 30, 2024SaltPlant
Nutrition
Corporate
& Other(a)
Total
Sales to external customers$160.6 $38.8 $3.5 $202.9 
Intersegment sales— 2.8 (2.8)— 
Shipping and handling cost48.2 5.0 — 53.2 
Operating earnings (loss)(c)(d)
25.9 (1.4)(18.6)5.9 
Depreciation, depletion and amortization15.7 8.6 1.8 26.1 
Total assets (as of end of period)1,013.3 408.1 173.8 1,595.2 

Three Months Ended June 30, 2023SaltPlant
Nutrition
Corporate
& Other(a)
Total
Sales to external customers$155.5 $47.5 $4.6 $207.6 
Intersegment sales— 2.8 (2.8)— 
Shipping and handling cost48.2 5.6 — 53.8 
Operating earnings (loss)(d)
21.7 2.5 (24.8)(0.6)
Depreciation, depletion and amortization14.2 8.2 1.9 24.3 
Total assets (as of end of period)970.1 477.1 286.3 1,733.5 
Nine Months Ended June 30, 2024SaltPlant
Nutrition
Corporate
& Other(a)
Total
Sales to external customers$745.3 $138.6 $24.7 $908.6 
Intersegment sales— 6.6 (6.6)— 
Shipping and handling cost235.9 18.6 0.6 255.1 
Operating earnings (loss)(b)(c)(d)
142.6 (56.7)(172.9)(87.0)
Depreciation, depletion and amortization47.1 25.7 5.6 78.4 

Nine Months Ended June 30, 2023SaltPlant
Nutrition
Corporate
& Other(a)
Total
Sales to external customers$824.1 $136.8 $10.2 $971.1 
Intersegment sales— 7.1 (7.1)— 
Shipping and handling cost274.9 16.4 — 291.3 
Operating earnings (loss)(c)(d)
141.9 12.8 (79.5)75.2 
Depreciation, depletion and amortization42.9 24.6 5.2 72.7 
Schedule of Disaggregated Revenue by Product Type
Disaggregated revenue by product type is as follows (in millions):
Three Months Ended June 30, 2024SaltPlant
Nutrition
Corporate
& Other(a)
Total
Highway Deicing Salt$84.1 $— $— $84.1 
Consumer & Industrial Salt76.5 — — 76.5 
SOP— 41.6 — 41.6 
Eliminations & Other— (2.8)3.5 0.7 
Sales to external customers$160.6 $38.8 $3.5 $202.9 

Three Months Ended June 30, 2023SaltPlant
Nutrition
Corporate
& Other(a)
Total
Highway Deicing Salt$79.0 $— $— $79.0 
Consumer & Industrial Salt76.5 — — 76.5 
SOP— 50.3 — 50.3 
Fire Retardant— — 1.9 1.9 
Eliminations & Other— (2.8)2.7 (0.1)
Sales to external customers$155.5 $47.5 $4.6 $207.6 

Nine Months Ended June 30, 2024SaltPlant
Nutrition
Corporate
& Other(a)
Total
Highway Deicing Salt$471.1 $— $— $471.1 
Consumer & Industrial Salt274.2 — — 274.2 
SOP— 145.2 — 145.2 
Fire Retardant— — 14.1 14.1 
Revenue from Services— — 0.5 0.5 
Eliminations & Other— (6.6)10.1 3.5 
Sales to external customers$745.3 $138.6 $24.7 $908.6 
Nine Months Ended June 30, 2023SaltPlant
Nutrition
Corporate
& Other(a)
Total
Highway Deicing Salt$543.0 $— $— $543.0 
Consumer & Industrial Salt281.1 — — 281.1 
SOP— 143.9 — 143.9 
Fire Retardant— — 1.9 1.9 
Eliminations & Other— (7.1)8.3 1.2 
Sales to external customers$824.1 $136.8 $10.2 $971.1 
(a)Corporate and Other includes corporate entities, records management operations, the Fortress fire retardant business, equity method investments, lithium costs and other incidental operations and eliminations. Operating earnings (loss) for corporate and other includes indirect corporate overhead, including costs for general corporate governance and oversight, lithium-related expenses, as well as costs for the human resources, information technology, legal and finance functions.
(b)The Company recognized impairments of $175.8 million for the nine months ended June 30, 2024, which impacted operating results. Refer to Note 1 for additional information regarding the Plant Nutrition and Fortress impairments and Note 5 for additional information about the impairment of lithium development assets.
(c)Corporate operating results were impacted by net gains of $0.9 million and $23.1 million related to the decline in the valuation of the Fortress contingent consideration for the three and nine months ended June 30, 2024, respectively. Corporate operating results also include net reimbursements related to the settled SEC investigation of $0.1 million for the nine months ended June 30, 2023. Refer to Note 9 for more information regarding the SEC investigation and settlement and Note 13 for information regarding the Fortress contingent consideration.
(d)The Company continued to take steps to align its cost structure to its current business needs. These initiatives impacted Corporate operating results and resulted in net severance and related charges for reductions in workforce and changes to executive leadership and additional restructuring costs related to the termination of the Company’s lithium development project of $1.5 million and $17.2 million for the three and nine months ended June 30, 2024, respectively, and $2.2 million and $5.5 million for the three and nine months ended June 30, 2023, respectively.
Schedule of Revenue by Geographic Area
The Company’s revenue by geographic area is as follows (in millions):
Three Months Ended
June 30,
Nine Months Ended
June 30,
Revenue2024202320242023
United States(a)
$158.4 $164.4 $679.4 $695.7 
Canada35.7 35.9 191.4 224.5 
United Kingdom7.9 6.6 35.0 43.9 
Other0.9 0.7 2.8 7.0 
Total revenue$202.9 $207.6 $908.6 $971.1 
(a)United States sales exclude product sold to foreign customers at U.S. ports.
v3.24.3
Stockholders' Equity and Equity Instruments (Tables)
9 Months Ended
Jun. 30, 2024
Equity [Abstract]  
Schedule of Stock-Based Compensation Activity
The following table summarizes stock-based compensation activity during the nine months ended June 30, 2024:
 Stock OptionsRSUs
PSUs(a)
 NumberWeighted-average
exercise price
NumberWeighted-average
fair value
NumberWeighted-average
fair value
Outstanding at September 30, 2023
642,995 $59.46 393,240 $42.50 393,579 $71.37 
Granted— — 533,399 25.55 276,916 24.69 
Exercised(b)
— — — — — — 
Released from restriction(b)
— — (252,798)40.18 — — 
Cancelled/expired(443,227)57.97 (202,439)32.54 (425,561)56.85 
Outstanding at June 30, 2024
199,768 $62.78 471,402 $28.84 244,934 $43.88 
(a)Until the performance period is completed, PSUs are included in the table at the target level at their grant date and at that level represent one share of common stock per PSU.
(b)Common stock issued for exercised options and for vested and earned RSUs and PSUs was issued from treasury stock.
Schedule of Components and Changes in Accumulated Other Comprehensive Income (Loss) The components of and changes in AOCL are as follows (in millions):
Three Months Ended June 30, 2024(a)
Gains and (Losses) on Cash Flow HedgesDefined Benefit PensionOther Post-Employment BenefitsForeign CurrencyTotal
Beginning balance$(2.6)$(6.2)$1.7 $(96.5)$(103.6)
Other comprehensive loss before reclassifications(b)
(0.6)— — (4.9)(5.5)
Amounts reclassified from AOCL1.5 0.3 (0.1)— 1.7 
Net current period other comprehensive income (loss)
0.9 0.3 (0.1)(4.9)(3.8)
Ending balance$(1.7)$(5.9)$1.6 $(101.4)$(107.4)

Three Months Ended June 30, 2023(a)
Gains and (Losses) on Cash Flow Hedges
Defined Benefit PensionOther Post-Employment BenefitsForeign CurrencyTotal
Beginning balance$(5.5)$(2.6)$1.3 $(97.8)$(104.6)
Other comprehensive income before reclassifications(b)
0.4 — — 11.8 12.2 
Amounts reclassified from AOCL1.8 — — — 1.8 
Net current period other comprehensive income
2.2 — — 11.8 14.0 
Ending balance$(3.3)$(2.6)$1.3 $(86.0)$(90.6)
Nine Months Ended June 30, 2024(a)
Gains and (Losses) on Cash Flow HedgesDefined Benefit PensionOther Post-Employment BenefitsForeign CurrencyTotal
Beginning balance$(1.4)$(6.6)$1.7 $(98.4)$(104.7)
Other comprehensive loss before reclassifications(b)
(3.4)— — (3.0)(6.4)
Amounts reclassified from AOCL3.1 0.7 (0.1)— 3.7 
Net current period other comprehensive (loss) income(0.3)0.7 (0.1)(3.0)(2.7)
Ending balance$(1.7)$(5.9)$1.6 $(101.4)$(107.4)

Nine Months Ended June 30, 2023(a)
Gains and (Losses) on Cash Flow HedgesDefined Benefit PensionOther Post-Employment BenefitsForeign CurrencyTotal
Beginning balance$(1.6)$(2.7)$1.3 $(112.3)$(115.3)
Other comprehensive (loss) income before reclassifications(b)
(3.8)— — 26.3 22.5 
Amounts reclassified from AOCL2.1 0.1 — — 2.2 
Net current period other comprehensive (loss) income(1.7)0.1 — 26.3 24.7 
Ending balance$(3.3)$(2.6)$1.3 $(86.0)$(90.6)
(a)With the exception of the CTA, for which no tax effect is recorded, the changes in the components of AOCL presented in the tables above are reflected net of applicable income taxes.
(b)The Company recorded foreign exchange gain (loss) of $1.0 million and $1.0 million in the three and nine months ended June 30, 2024, respectively, and $(2.0) million and $(3.4) million in the three and nine months ended June 30, 2023, respectively, in AOCL related to intercompany notes which were deemed to be of a long-term investment nature.
Schedule of Amounts Reclassified from AOCL to Expense (Income)
The amounts reclassified from AOCL to expense (income) for the three and nine months ended June 30, 2024 and 2023, are shown below (in millions):
Amount Reclassified from AOCL
 Three Months Ended
June 30,
Nine Months Ended
June 30,
Line Item Impacted in the
Consolidated Statements of Operations
2024202320242023
Loss (gain) on cash flow hedges:
Natural gas instruments$1.5 $2.4 $3.1 $2.9 Product cost
Income tax expense— (0.6)— (0.8)
Reclassifications, net of income taxes1.5 1.8 3.1 2.1 
Amortization of defined benefit pension: 
Amortization of loss0.3 — 0.9 0.1 Product cost
Income tax benefit— — (0.2)— 
Reclassifications, net of income taxes0.3 — 0.7 0.1  
Amortization of other post-employment benefits:
Amortization of gain(0.1)— (0.1)— Product cost
Income tax expense— — — — 
Reclassifications, net of income taxes(0.1)— (0.1)— 
Total reclassifications, net of income taxes$1.7 $1.8 $3.7 $2.2  
v3.24.3
Derivative Financial Instruments (Tables)
9 Months Ended
Jun. 30, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Schedule of Fair Value of Derivatives
The following tables present the fair value of the Company’s derivatives (in millions):
 Asset DerivativesLiability Derivatives
Consolidated Balance Sheet LocationJune 30, 2024Consolidated Balance Sheet LocationJune 30, 2024
Derivatives designated as hedging instruments:
Commodity contractsOther current assets$0.9 Accrued expenses and other current liabilities$2.4 
Commodity contractsOther assets0.2 Other noncurrent liabilities0.4 
Total derivatives designated as hedging instruments1.1 2.8 
Derivatives not designated as hedging instruments:
Commodity contractsOther current assets— Accrued expenses and other current liabilities0.1 
Total derivatives not designated as hedging instruments— 0.1 
Total derivatives(a)
$1.1 $2.9 
(a)The Company has master netting agreements with its commodity hedge counterparties and accordingly has netted in its Consolidated Balance Sheets $1.1 million of its commodity contracts that are in receivable positions against its contracts in payable positions.

 Asset DerivativesLiability Derivatives
Consolidated Balance Sheet LocationSeptember 30, 2023Consolidated Balance Sheet LocationSeptember 30, 2023
Derivatives designated as hedging instruments:
Commodity contractsOther current assets$0.9 Accrued expenses and other current liabilities$2.3 
Total derivatives designated as hedging instruments0.9 2.3 
Derivatives not designated as hedging instruments:
Commodity contractsOther current assets0.1 Accrued expenses and other current liabilities— 
Total derivatives not designated as hedging instruments0.1 — 
Total derivatives(a)
$1.0 $2.3 
(a)The Company has master netting agreements with its commodity hedge counterparties and accordingly has netted in its Consolidated Balance Sheets $1.0 million of its commodity contracts that are in receivable positions against its contracts in payable positions.
v3.24.3
Fair Value Measurements (Tables)
9 Months Ended
Jun. 30, 2024
Fair Value Disclosures [Abstract]  
Schedule of Estimated Fair Values for Type of Instrument
The estimated fair values for each type of instrument are presented below (in millions):
 June 30,
2024
Level OneLevel TwoLevel Three
Asset Class:
Mutual fund investments in a non-qualified savings plan(a)
$3.1 $3.1 $— $— 
Total Assets$3.1 $3.1 $— $— 
Liability Class:    
Derivatives designated as hedging instruments - natural gas instruments, net$(1.7)$— $(1.7)$— 
Derivatives not designated as hedging instruments - natural gas instruments, net(0.1)— (0.1)— 
Liabilities related to non-qualified savings plan(3.1)(3.1)— — 
Total Liabilities$(4.9)$(3.1)$(1.8)$— 
(a)Includes mutual fund investments of approximately 30% in common stock of large-cap U.S. companies, 5% in common stock of small to mid-cap U.S. companies, 5% in international companies, 15% in bond funds, 5% in short-term investments and 40% in blended funds.

 September 30,
2023
 
Level One
 
Level Two
 
Level Three
Asset Class:
Mutual fund investments in a non-qualified savings plan(a)
$2.6 $2.6 $— $— 
Derivatives not designated as hedging instruments - natural gas instruments, net0.1 — 0.1 — 
Total Assets$2.7 $2.6 $0.1 $— 
Liability Class:    
Derivatives designated as hedging instruments - natural gas instruments, net$(1.4)$— $(1.4)$— 
Liabilities related to non-qualified savings plan(2.6)(2.6)— — 
Total Liabilities$(4.0)$(2.6)$(1.4)$— 
(a)Includes mutual fund investments of approximately 25% in the common stock of large-cap U.S. companies, 5% in the common stock of small to mid-cap U.S. companies, 10% in the common stock of international companies, 10% in bond funds, 5% in short-term investments and 45% in blended funds.
Schedule of Total Contingent Consideration
The following table presents the fair value of the Company’s total contingent consideration arrangement (in millions):
Consolidated Balance Sheet LocationJune 30, 2024September 30, 2023
Accrued expenses and other current liabilities$— $7.3 
Other noncurrent liabilities6.9 31.8 
Total contingent consideration(a)
$6.9 $39.1 
(a)The decrease in total contingent consideration was related to a net $23.1 million decrease in the fair value of the remaining contingent consideration, discussed further above, and $9.1 million of payments made during the nine months ended June 30, 2024.
v3.24.3
Earnings per Share (Tables)
9 Months Ended
Jun. 30, 2024
Earnings Per Share [Abstract]  
Schedule of Computation of Basic and Diluted Earnings Per Common Share The following table sets forth the computation of basic and diluted earnings per common share (in millions, except for share and per-share data):
 Three Months Ended
June 30,
Nine Months Ended
June 30,
 2024202320242023
Numerator:
Net (loss) earnings$(43.6)$36.4 $(157.8)$14.5 
Less: net earnings allocated to participating securities(a)
— (0.4)(0.2)(0.2)
Net (loss) earnings available to common stockholders$(43.6)$36.0 $(158.0)$14.3 
Denominator (in thousands):
Weighted-average common shares outstanding, shares for basic earnings per share41,342 41,142 41,284 40,663 
Weighted-average awards outstanding(b)
— — — — 
Shares for diluted earnings per share41,342 41,142 41,284 40,663 
Basic net (loss) earnings per common share$(1.05)$0.88 $(3.83)$0.35 
Diluted net (loss) earnings per common share$(1.05)$0.88 $(3.83)$0.35 
(a)Weighted participating securities include RSUs and PSUs that receive non-forfeitable dividends and consist of 632,000 and 698,000 weighted participating securities for the three and nine months ended June 30, 2024, respectively, and 453,000 and 469,000 weighted participating securities for the three and nine months ended June 30, 2023, respectively.
(b)For the calculation of diluted net earnings (loss) per share, the Company uses the more dilutive of either the treasury stock method or the two-class method to determine the weighted-average number of outstanding common shares. In addition, the Company had 874,000 and 1,427,000 weighted-average equity awards outstanding for the three and nine months ended June 30, 2024, respectively, and 1,151,000 and 1,267,000 weighted-average equity awards outstanding for the three and nine months ended June 30, 2023, respectively, that were anti-dilutive.
v3.24.3
Accounting Policies and Basis of Presentation - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Mar. 31, 2024
Jun. 30, 2024
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Goodwill, loss on impairment $ 83.0 $ 83.0
Corporate & Other    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Goodwill, loss on impairment 32.0 32.0
Developed Technology    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Impairment of intangible asset   15.6
Plant Nutrition    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Goodwill, loss on impairment $ 51.0 51.0
Inventories    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Impairment of finished goods   $ 2.4
v3.24.3
Accounting Policies and Basis of Presentation - Schedule of Impairments Incurred (Details)
$ in Millions
9 Months Ended
Jun. 30, 2024
USD ($)
Impaired Long-Lived Assets Held and Used [Line Items]  
Impairment $ 175.8
Corporate & Other | Lithium long-lived assets, net  
Impaired Long-Lived Assets Held and Used [Line Items]  
Impairment 74.8
Corporate & Other | Fortress goodwill  
Impaired Long-Lived Assets Held and Used [Line Items]  
Impairment 32.0
Corporate & Other | Fortress long-lived assets, net  
Impaired Long-Lived Assets Held and Used [Line Items]  
Impairment 15.6
Corporate & Other | Fortress inventory  
Impaired Long-Lived Assets Held and Used [Line Items]  
Impairment 2.4
Plant Nutrition | Plant Nutrition goodwill  
Impaired Long-Lived Assets Held and Used [Line Items]  
Impairment $ 51.0
v3.24.3
Business Acquisition (Details) - USD ($)
$ in Millions
9 Months Ended
May 05, 2023
Jun. 30, 2024
Jun. 30, 2023
Sep. 30, 2023
Business Acquisition [Line Items]        
Acquisition of business, net of cash acquired   $ 0.0 $ 18.9  
Contingent consideration, liability   $ 6.9   $ 39.1
Fortress        
Business Acquisition [Line Items]        
Ownership interest in investment 45.00%      
Fortress        
Business Acquisition [Line Items]        
Remaining interest acquired (as a percent) 55.00%      
Acquisition of business, net of cash acquired $ 18.9      
Cash held by acquiree 6.5      
Contingent consideration, liability $ 28.0      
Performance period 5 years      
Contingent consideration period 10 years      
v3.24.3
Revenues (Details) - USD ($)
$ in Millions
Jun. 30, 2024
Sep. 30, 2023
Revenue from Contract with Customer [Abstract]    
Deferred revenue $ 3.6 $ 8.5
v3.24.3
Inventories (Details) - USD ($)
$ in Millions
Jun. 30, 2024
Sep. 30, 2023
Inventory Disclosure [Abstract]    
Finished goods $ 315.3 $ 319.3
Work in process 7.3 7.3
Raw materials and supplies 84.9 72.9
Total inventories 407.5 399.5
Raw materials and supplies, noncurrent $ 35.6 $ 35.8
v3.24.3
Property, Plant and Equipment, Net - Schedule of Property, Plant and Equipment, Net (Details) - USD ($)
$ in Millions
Jun. 30, 2024
Sep. 30, 2023
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross $ 1,940.1 $ 1,953.9
Less: accumulated depreciation and depletion (1,152.2) (1,101.4)
Property, plant and equipment, net 787.9 852.5
Land, buildings and structures, and leasehold improvements    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 552.6 547.9
Machinery and equipment    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 1,127.9 1,102.0
Office furniture and equipment    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 22.4 21.6
Mineral interests    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 169.2 169.1
Construction in progress    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross $ 68.0 $ 113.3
v3.24.3
Property, Plant and Equipment, Net - Narrative (Details)
$ in Millions
9 Months Ended
Jun. 30, 2024
USD ($)
Property, Plant and Equipment [Line Items]  
Impairment $ 175.8
Loss on impairment of long-lived assets, future commitments 5.3
Lithium Salt Resource  
Property, Plant and Equipment [Line Items]  
Property, plant and equipment 72.7
Property, plant and equipment remaining 5.1
Corporate & Other | Lithium long-lived assets, net  
Property, Plant and Equipment [Line Items]  
Impairment $ 74.8
v3.24.3
Goodwill and Intangible Assets - Schedule of Changes in the Carrying Amount of Goodwill (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Mar. 31, 2024
Dec. 31, 2023
Jun. 30, 2024
Goodwill [Roll Forward]        
Goodwill, beginning balance $ 5.9 $ 89.2 $ 88.8 $ 88.8
Foreign currency translation adjustment 0.0 (0.3) 0.4  
Impairments   (83.0)   (83.0)
Goodwill, ending balance 5.9 5.9 89.2 5.9
Corporate & Other        
Goodwill [Roll Forward]        
Goodwill, beginning balance 5.9 37.9 37.7 37.7
Foreign currency translation adjustment 0.0 0.0 0.2  
Impairments   (32.0)   (32.0)
Goodwill, ending balance 5.9 5.9 37.9 5.9
Plant Nutrition        
Goodwill [Roll Forward]        
Goodwill, beginning balance 0.0 51.3 51.1 51.1
Foreign currency translation adjustment 0.0 (0.3) 0.2  
Impairments   (51.0)   (51.0)
Goodwill, ending balance $ 0.0 $ 0.0 $ 51.3 $ 0.0
v3.24.3
Goodwill and Intangible Assets - Narrative (Details)
$ in Millions
9 Months Ended
Jun. 30, 2024
USD ($)
Indefinite-Lived, In-Process Research and Development  
Indefinite-Lived Intangible Assets [Line Items]  
Indefinite-lived intangible assets $ 2.2
Developed Technology  
Indefinite-Lived Intangible Assets [Line Items]  
Impairment of intangible asset 15.6
Accumulated amortization 0.4
Customer Relationships  
Indefinite-Lived Intangible Assets [Line Items]  
Net intangible assets 54.6
Trade Names  
Indefinite-Lived Intangible Assets [Line Items]  
Net intangible assets $ 0.2
v3.24.3
Income Taxes (Details) - USD ($)
$ in Millions
9 Months Ended
Jun. 30, 2024
Sep. 30, 2023
Income Tax Disclosure [Line Items]    
Nondeductible executive compensation $ 1.0  
Prepaid taxes 11.2 $ 11.0
U.S. Federal    
Income Tax Disclosure [Line Items]    
Deferred tax asset valuation allowance recorded 28.0  
Foreign Tax Authority    
Income Tax Disclosure [Line Items]    
Net operating loss carryforwards 65.5 65.4
Foreign Tax Authority | Canadian Tax Authority    
Income Tax Disclosure [Line Items]    
Total reassessments including interest 190.4  
Amount of security posted in the form of a performance bond 160.1  
Amount of security posted in the form of cash 36.3 36.3
State and Local | NOL Carryforwards Expire Beginning in 2035    
Income Tax Disclosure [Line Items]    
Net operating loss carryforwards $ 2.9 $ 2.9
v3.24.3
Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($)
$ in Millions
Jun. 30, 2024
Sep. 30, 2023
Debt Instrument [Line Items]    
Long-term debt, gross $ 880.7 $ 811.2
Less unamortized debt issuance costs (5.6) (5.9)
Total debt 875.1 805.3
Less current portion (6.3) (5.0)
Long-term debt $ 868.8 $ 800.3
Senior Notes | 6.75% Senior Notes due December 2027    
Debt Instrument [Line Items]    
Stated interest rate (as a percent) 6.75% 6.75%
Long-term debt, gross $ 500.0 $ 500.0
Line of Credit | Term Loan due May 2028    
Debt Instrument [Line Items]    
Long-term debt, gross 195.0 198.8
Line of Credit | Revolving Credit Facility due May 2028    
Debt Instrument [Line Items]    
Long-term debt, gross 151.9 81.5
Line of Credit | AR Securitization Facility expires March 2027    
Debt Instrument [Line Items]    
Long-term debt, gross $ 33.8 $ 30.9
v3.24.3
Long-Term Debt - Narrative (Details)
$ in Millions
6 Months Ended
Mar. 31, 2024
USD ($)
Sep. 18, 2024
Aug. 12, 2024
Jun. 30, 2024
USD ($)
Mar. 27, 2024
USD ($)
Sep. 30, 2023
Debt Instrument [Line Items]            
Compliance certification, period due       45 days    
Subsequent Event            
Debt Instrument [Line Items]            
Compliance certification, period due     75 days      
Account Receivable Financing Receivable            
Debt Instrument [Line Items]            
Fees paid for extension         $ 0.4  
Line of Credit | 2023 Credit Agreement            
Debt Instrument [Line Items]            
Deferred financing costs         $ 1.7  
Additional legal fees $ 0.9          
Line of Credit | 2023 Credit Agreement | Fiscal Quarter Ended December 31, 2024            
Debt Instrument [Line Items]            
Consolidated total net leverage ratio         6.5  
Line of Credit | 2023 Credit Agreement | Fiscal Quarter Ended March 31, 2026 and Thereafter            
Debt Instrument [Line Items]            
Consolidated total net leverage ratio         4.75  
Line of Credit | Revolving Credit Facility Due January 2025            
Debt Instrument [Line Items]            
Weighted average interest rate of debt (as a percent)       8.00%   7.80%
Line of Credit | Revolving Credit Facility Due January 2025 | Minimum            
Debt Instrument [Line Items]            
Weighted average interest rate of debt (as a percent)       7.90%   7.70%
Line of Credit | Revolving Credit Facility Due January 2025 | Maximum            
Debt Instrument [Line Items]            
Weighted average interest rate of debt (as a percent)       10.00%   9.80%
Line of Credit | Revolving Credit Facility | 2023 Credit Agreement            
Debt Instrument [Line Items]            
Availability under revolving credit facility       $ 208.0    
Aggregate principal amount of credit facility       375.0    
Line of Credit | Revolving Credit Facility | Revolving Credit Facility Due January 2025            
Debt Instrument [Line Items]            
Maximum unrestricted cash       $ 75.0    
Senior Notes | 6.75% Senior Notes due December 2027            
Debt Instrument [Line Items]            
Stated interest rate (as a percent)       6.75%   6.75%
Senior Notes | 6.75% Senior Notes due December 2027 | Subsequent Event            
Debt Instrument [Line Items]            
Stated interest rate (as a percent)   6.75%        
v3.24.3
Commitments and Contingencies (Details)
$ in Millions
Apr. 24, 2024
officer
Sep. 23, 2022
USD ($)
Sep. 30, 2023
USD ($)
SEC Investigation      
Loss Contingencies [Line Items]      
Loss contingency, damages sought, value | $   $ 12  
Contingent loss accrual | $     $ 10
Class Action Lawsuit Filed in District of Kansas | Former Officer | Pending Litigation      
Loss Contingencies [Line Items]      
Number of defendants | officer 2    
Class Action Lawsuit Filed in District of Kansas | Current Officer | Pending Litigation      
Loss Contingencies [Line Items]      
Number of defendants | officer 2    
v3.24.3
Operating Segments - Narrative (Details) - segment
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Segment Reporting [Abstract]        
Number of reportable segments 2 2 2 2
v3.24.3
Operating Segments - Schedule of Segment Information (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Segment Reporting Information [Line Items]        
Sales to external customers $ 202.9 $ 207.6 $ 908.6 $ 971.1
Operating earnings (loss) 5.9 (0.6) (87.0) 75.2
Depreciation, depletion and amortization 26.1 24.3 78.4 72.7
Total assets (as of end of period) 1,595.2 1,733.5 1,595.2 1,733.5
Shipping and handling cost        
Segment Reporting Information [Line Items]        
Shipping and handling cost 53.2 53.8 255.1 291.3
Operating Segments | Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 160.6 155.5 745.3 824.1
Operating earnings (loss) 25.9 21.7 142.6 141.9
Depreciation, depletion and amortization 15.7 14.2 47.1 42.9
Total assets (as of end of period) 1,013.3 970.1 1,013.3 970.1
Operating Segments | Salt | Shipping and handling cost        
Segment Reporting Information [Line Items]        
Shipping and handling cost 48.2 48.2 235.9 274.9
Operating Segments | Plant Nutrition        
Segment Reporting Information [Line Items]        
Sales to external customers 38.8 47.5 138.6 136.8
Operating earnings (loss) (1.4) 2.5 (56.7) 12.8
Depreciation, depletion and amortization 8.6 8.2 25.7 24.6
Total assets (as of end of period) 408.1 477.1 408.1 477.1
Operating Segments | Plant Nutrition | Shipping and handling cost        
Segment Reporting Information [Line Items]        
Shipping and handling cost 5.0 5.6 18.6 16.4
Corporate & Other        
Segment Reporting Information [Line Items]        
Sales to external customers 3.5 4.6 24.7 10.2
Operating earnings (loss) (18.6) (24.8) (172.9) (79.5)
Depreciation, depletion and amortization 1.8 1.9 5.6 5.2
Total assets (as of end of period) 173.8 286.3 173.8 286.3
Corporate & Other | Shipping and handling cost        
Segment Reporting Information [Line Items]        
Shipping and handling cost 0.0 0.0 0.6 0.0
Intersegment Eliminations        
Segment Reporting Information [Line Items]        
Sales to external customers (2.8) (2.8) (6.6) (7.1)
Intersegment Eliminations | Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 0.0 0.0 0.0 0.0
Intersegment Eliminations | Plant Nutrition        
Segment Reporting Information [Line Items]        
Sales to external customers $ 2.8 $ 2.8 $ 6.6 $ 7.1
v3.24.3
Operating Segments - Schedule of Disaggregated Revenue by Product Type (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Segment Reporting Information [Line Items]        
Sales to external customers $ 202.9 $ 207.6 $ 908.6 $ 971.1
Impairment     175.8  
Increase to contingent consideration liability     (23.1) 0.0
Accrued loss reserve       (0.1)
Severance costs 1.5   17.2  
Restructuring charges   2.2   5.5
Fortress        
Segment Reporting Information [Line Items]        
Increase to contingent consideration liability 0.9   23.1  
Highway Deicing Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 84.1 79.0 471.1 543.0
Consumer & Industrial Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 76.5 76.5 274.2 281.1
SOP        
Segment Reporting Information [Line Items]        
Sales to external customers 41.6 50.3 145.2 143.9
Fire Retardant        
Segment Reporting Information [Line Items]        
Sales to external customers   1.9 14.1 1.9
Revenue from Services        
Segment Reporting Information [Line Items]        
Sales to external customers     0.5  
Eliminations & Other        
Segment Reporting Information [Line Items]        
Sales to external customers 0.7 (0.1)    
Operating Segments | Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 160.6 155.5 745.3 824.1
Operating Segments | Plant Nutrition        
Segment Reporting Information [Line Items]        
Sales to external customers 38.8 47.5 138.6 136.8
Operating Segments | Highway Deicing Salt | Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 84.1 79.0 471.1 543.0
Operating Segments | Highway Deicing Salt | Plant Nutrition        
Segment Reporting Information [Line Items]        
Sales to external customers 0.0 0.0 0.0 0.0
Operating Segments | Consumer & Industrial Salt | Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 76.5 76.5 274.2 281.1
Operating Segments | Consumer & Industrial Salt | Plant Nutrition        
Segment Reporting Information [Line Items]        
Sales to external customers 0.0 0.0 0.0 0.0
Operating Segments | SOP | Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 0.0 0.0 0.0 0.0
Operating Segments | SOP | Plant Nutrition        
Segment Reporting Information [Line Items]        
Sales to external customers 41.6 50.3 145.2 143.9
Operating Segments | Fire Retardant | Salt        
Segment Reporting Information [Line Items]        
Sales to external customers   0.0 0.0 0.0
Operating Segments | Fire Retardant | Plant Nutrition        
Segment Reporting Information [Line Items]        
Sales to external customers   0.0 0.0 0.0
Operating Segments | Revenue from Services | Salt        
Segment Reporting Information [Line Items]        
Sales to external customers     0.0  
Operating Segments | Revenue from Services | Plant Nutrition        
Segment Reporting Information [Line Items]        
Sales to external customers     0.0  
Operating Segments | Eliminations & Other | Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 0.0 0.0 0.0 0.0
Operating Segments | Eliminations & Other | Plant Nutrition        
Segment Reporting Information [Line Items]        
Sales to external customers (2.8) (2.8) (6.6) (7.1)
Corporate & Other        
Segment Reporting Information [Line Items]        
Sales to external customers 3.5 4.6 24.7 10.2
Corporate & Other | Highway Deicing Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 0.0 0.0 0.0 0.0
Corporate & Other | Consumer & Industrial Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 0.0 0.0 0.0 0.0
Corporate & Other | SOP        
Segment Reporting Information [Line Items]        
Sales to external customers 0.0 0.0 0.0 0.0
Corporate & Other | Fire Retardant        
Segment Reporting Information [Line Items]        
Sales to external customers   1.9 14.1 1.9
Corporate & Other | Revenue from Services        
Segment Reporting Information [Line Items]        
Sales to external customers     0.5  
Corporate & Other | Eliminations & Other        
Segment Reporting Information [Line Items]        
Sales to external customers 3.5 2.7 10.1 8.3
Intersegment Eliminations        
Segment Reporting Information [Line Items]        
Sales to external customers (2.8) (2.8) (6.6) (7.1)
Intersegment Eliminations | Salt        
Segment Reporting Information [Line Items]        
Sales to external customers 0.0 0.0 0.0 0.0
Intersegment Eliminations | Plant Nutrition        
Segment Reporting Information [Line Items]        
Sales to external customers $ 2.8 $ 2.8 6.6 7.1
Intersegment Eliminations | Eliminations & Other        
Segment Reporting Information [Line Items]        
Sales to external customers     $ 3.5 $ 1.2
v3.24.3
Operating Segments - Schedule of Revenue by Geographic Area (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Segment Reporting Information [Line Items]        
Total revenue $ 202.9 $ 207.6 $ 908.6 $ 971.1
United States        
Segment Reporting Information [Line Items]        
Total revenue 158.4 164.4 679.4 695.7
Canada        
Segment Reporting Information [Line Items]        
Total revenue 35.7 35.9 191.4 224.5
United Kingdom        
Segment Reporting Information [Line Items]        
Total revenue 7.9 6.6 35.0 43.9
Other        
Segment Reporting Information [Line Items]        
Total revenue $ 0.9 $ 0.7 $ 2.8 $ 7.0
v3.24.3
Stockholders' Equity and Equity Instruments - Narrative (Details) - USD ($)
$ in Millions
1 Months Ended 9 Months Ended
Mar. 31, 2024
Feb. 28, 2022
Jun. 30, 2024
Jun. 30, 2023
May 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Treasury stock reissued (in shares)     158,132    
Tax deficiency from equity compensation awards recorded as an increase to income tax expense     $ 1.0    
Share-based payment arrangement, expense     8.1 $ 17.7  
Compensation expense to be paid in cash     $ 1.8 $ 0.5  
RSUs          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Reissued share of treasury stock (in shares)     252,798    
Stock Payments          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Reissued share of treasury stock (in shares)     46,039    
Equity Awards          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares withheld related to vesting of RSUs and PSUs (in shares)     96,088    
Fair value of stock withheld related to vesting of RSUs and PSUs     $ 2.1    
Scorecard PSUs | Minimum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based compensation payment award performance percentage     0.00%    
Scorecard PSUs | Maximum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based compensation payment award performance percentage     300.00%    
2020 Incentive Award Plan          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares authorized for issuance (in shares)         2,977,933
Shares authorized for issuance (in shares) 3,000,000 750,000      
v3.24.3
Stockholders' Equity and Equity Instruments - Schedule of Stock-Based Compensation Activity (Details)
9 Months Ended
Jun. 30, 2024
$ / shares
shares
Stock Options  
Number  
Outstanding at beginning of period (in shares) 642,995
Granted (in shares) 0
Exercised (in shares) 0
Released from restriction (in shares) 0
Cancelled/expired (in shares) (443,227)
Outstanding at end of period (in shares) 199,768
Weighted-average exercise price  
Weighted-average exercise price at beginning of period (in dollars per share) | $ / shares $ 59.46
Weighted-average exercise price, granted (in dollars per share) | $ / shares 0
Weighted-average exercise price, exercised (in dollars per share) | $ / shares 0
Weighted-average exercise price, released from restriction (in dollars per share) | $ / shares 0
Weighted-average exercise price, cancelled/expired (in dollars per share) | $ / shares 57.97
Weighted-average exercise price at end of period (in dollars per share) | $ / shares $ 62.78
RSUs  
Number  
Outstanding at beginning of period (in shares) 393,240
Granted (in shares) 533,399
Exercised (in shares) 0
Released from restriction (in shares) (252,798)
Cancelled/expired (in shares) (202,439)
Outstanding at end of period (in shares) 471,402
Weighted-average fair value  
Weighted-average fair value at beginning of period (in dollars per share) | $ / shares $ 42.50
Weighted-average fair value, granted (in dollars per share) | $ / shares 25.55
Weighted-average fair value, exercised (in dollars per share) | $ / shares 0
Weighted-average fair value, released from restriction (in dollars per share) | $ / shares 40.18
Weighted-average fair value, cancelled/expired (in dollars per share) | $ / shares 32.54
Weighted-average fair value at end of period (in dollars per share) | $ / shares $ 28.84
PSUs  
Number  
Outstanding at beginning of period (in shares) 393,579
Granted (in shares) 276,916
Exercised (in shares) 0
Released from restriction (in shares) 0
Cancelled/expired (in shares) (425,561)
Outstanding at end of period (in shares) 244,934
Weighted-average fair value  
Weighted-average fair value at beginning of period (in dollars per share) | $ / shares $ 71.37
Weighted-average fair value, granted (in dollars per share) | $ / shares 24.69
Weighted-average fair value, exercised (in dollars per share) | $ / shares 0
Weighted-average fair value, released from restriction (in dollars per share) | $ / shares 0
Weighted-average fair value, cancelled/expired (in dollars per share) | $ / shares 56.85
Weighted-average fair value at end of period (in dollars per share) | $ / shares $ 43.88
PSU at grant date (in shares per unit) 1
v3.24.3
Stockholders' Equity and Equity Instruments - Schedule of Components and Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance $ 400.4 $ 494.2 $ 521.0 $ 265.2
Other comprehensive (loss) income before reclassifications (5.5) 12.2 (6.4) 22.5
Amounts reclassified from AOCL 1.7 1.8 3.7 2.2
Net current period other comprehensive income (loss) (3.8) 14.0 (2.7) 24.7
Ending balance 352.1 542.0 352.1 542.0
Gain (loss) on foreign exchange of intercompany notes of long-term nature 1.0 (2.0) 1.0 (3.4)
Total        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance (103.6) (104.6) (104.7) (115.3)
Ending balance (107.4) (90.6) (107.4) (90.6)
Gains and (Losses) on Cash Flow Hedges        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance (2.6) (5.5) (1.4) (1.6)
Other comprehensive (loss) income before reclassifications (0.6) 0.4 (3.4) (3.8)
Amounts reclassified from AOCL 1.5 1.8 3.1 2.1
Net current period other comprehensive income (loss) 0.9 2.2 (0.3) (1.7)
Ending balance (1.7) (3.3) (1.7) (3.3)
Benefit Plans        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance   (2.6)   (2.7)
Other comprehensive (loss) income before reclassifications   0.0   0.0
Amounts reclassified from AOCL   0.0   0.1
Net current period other comprehensive income (loss)   0.0   0.1
Ending balance   (2.6)   (2.6)
Benefit Plans | Defined Benefit Pension        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance (6.2)   (6.6)  
Other comprehensive (loss) income before reclassifications 0.0   0.0  
Amounts reclassified from AOCL 0.3   0.7  
Net current period other comprehensive income (loss) 0.3   0.7  
Ending balance (5.9)   (5.9)  
Benefit Plans | Other Post-Employment Benefits        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance 1.7 1.3 1.7 1.3
Other comprehensive (loss) income before reclassifications 0.0 0.0 0.0 0.0
Amounts reclassified from AOCL (0.1) 0.0 (0.1) 0.0
Net current period other comprehensive income (loss) (0.1) 0.0 (0.1) 0.0
Ending balance 1.6 1.3 1.6 1.3
Foreign Currency        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance (96.5) (97.8) (98.4) (112.3)
Other comprehensive (loss) income before reclassifications (4.9) 11.8 (3.0) 26.3
Amounts reclassified from AOCL 0.0 0.0 0.0 0.0
Net current period other comprehensive income (loss) (4.9) 11.8 (3.0) 26.3
Ending balance $ (101.4) $ (86.0) $ (101.4) $ (86.0)
v3.24.3
Stockholders' Equity and Equity Instruments - Schedule of Amounts Reclassified from AOCL to Expense (Income) (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Income tax benefit (expense) $ 32.7 $ (42.8) $ 20.4 $ 24.2
Reclassifications, net of income taxes (43.6) 36.4 (157.8) 14.5
Product cost        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Product cost (117.1) (119.2) (478.0) (490.0)
Amount Reclassified from AOCL        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Reclassifications, net of income taxes 1.7 1.8 3.7 2.2
Amount Reclassified from AOCL | Loss (gain) on cash flow hedges:        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Income tax benefit (expense) 0.0 (0.6) 0.0 (0.8)
Reclassifications, net of income taxes 1.5 1.8 3.1 2.1
Amount Reclassified from AOCL | Loss (gain) on cash flow hedges: | Natural gas instruments | Product cost        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Product cost 1.5 2.4 3.1 2.9
Amount Reclassified from AOCL | Amortization of defined benefit pension:        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Income tax benefit (expense) 0.0 0.0 (0.2) 0.0
Reclassifications, net of income taxes 0.3 0.0 0.7 0.1
Amount Reclassified from AOCL | Amortization of defined benefit pension: | Product cost        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Product cost 0.3 0.0 0.9 0.1
Amount Reclassified from AOCL | Amortization of other post-employment benefits:        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Income tax benefit (expense) 0.0 0.0 0.0 0.0
Reclassifications, net of income taxes (0.1) 0.0 (0.1) 0.0
Amount Reclassified from AOCL | Amortization of other post-employment benefits: | Product cost        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Product cost $ (0.1) $ 0.0 $ (0.1) $ 0.0
v3.24.3
Derivative Financial Instruments - Narrative (Details)
MMBTU in Millions, $ in Millions
3 Months Ended 9 Months Ended 12 Months Ended
Jun. 30, 2024
USD ($)
Jun. 30, 2023
USD ($)
Jun. 30, 2024
USD ($)
MMBTU
Jun. 30, 2023
USD ($)
Sep. 30, 2023
USD ($)
MMBTU
Mar. 01, 2023
USD ($)
Derivatives, Fair Value [Line Items]            
Liability Derivatives $ 2.9   $ 2.9   $ 2.3  
Expense recognized (0.3) $ (2.7) (1.9) $ (3.7)    
Net gains to be reclassified from accumulated other comprehensive loss to earnings during the next 12 months     1.5      
Derivatives Designated as Hedging Instruments            
Derivatives, Fair Value [Line Items]            
Liability Derivatives 2.8   2.8   2.3  
Derivatives Not Designated as Hedging Instrument            
Derivatives, Fair Value [Line Items]            
Liability Derivatives 0.1   $ 0.1   $ 0.0  
Natural gas instruments            
Derivatives, Fair Value [Line Items]            
Notional amount (in MMBtus) | MMBTU     2.9   2.3  
Expense recognized $ 0.1   $ 0.8      
Natural gas instruments | Derivatives Designated as Hedging Instruments            
Derivatives, Fair Value [Line Items]            
Percent of forecasted usage to be hedged 90.00%   90.00%      
Maximum period which the company hedges in advance of forecasted purchase     36 months      
Natural gas instruments | Derivatives Designated as Hedging Instruments | Accrued expenses and other current liabilities            
Derivatives, Fair Value [Line Items]            
Liability Derivatives $ 2.4   $ 2.4   $ 2.3  
Natural gas instruments | Derivatives Not Designated as Hedging Instrument | Accrued expenses and other current liabilities            
Derivatives, Fair Value [Line Items]            
Liability Derivatives $ 0.1   $ 0.1   $ 0.0 $ 0.1
v3.24.3
Derivative Financial Instruments - Schedule of Fair Value of Derivatives (Details) - USD ($)
$ in Millions
Jun. 30, 2024
Sep. 30, 2023
Mar. 01, 2023
Derivatives, Fair Value [Line Items]      
Asset Derivatives $ 1.1 $ 1.0  
Liability Derivatives 2.9 2.3  
Derivatives Designated as Hedging Instruments      
Derivatives, Fair Value [Line Items]      
Asset Derivatives 1.1 0.9  
Liability Derivatives 2.8 2.3  
Derivatives Not Designated as Hedging Instrument      
Derivatives, Fair Value [Line Items]      
Asset Derivatives 0.0 0.1  
Liability Derivatives 0.1 0.0  
Natural gas instruments      
Derivatives, Fair Value [Line Items]      
Netting of contracts in a receivable position against contracts in payable position 1.1 1.0  
Natural gas instruments | Derivatives Designated as Hedging Instruments | Other current assets      
Derivatives, Fair Value [Line Items]      
Asset Derivatives 0.9 0.9  
Natural gas instruments | Derivatives Designated as Hedging Instruments | Accrued expenses and other current liabilities      
Derivatives, Fair Value [Line Items]      
Liability Derivatives 2.4 2.3  
Natural gas instruments | Derivatives Designated as Hedging Instruments | Other assets      
Derivatives, Fair Value [Line Items]      
Asset Derivatives 0.2    
Natural gas instruments | Derivatives Designated as Hedging Instruments | Other noncurrent liabilities      
Derivatives, Fair Value [Line Items]      
Liability Derivatives 0.4    
Natural gas instruments | Derivatives Not Designated as Hedging Instrument | Other current assets      
Derivatives, Fair Value [Line Items]      
Asset Derivatives 0.0 0.1  
Natural gas instruments | Derivatives Not Designated as Hedging Instrument | Accrued expenses and other current liabilities      
Derivatives, Fair Value [Line Items]      
Liability Derivatives $ 0.1 $ 0.0 $ 0.1
v3.24.3
Fair Value Measurements - Schedule of Estimated Fair Values for Type of Instrument (Details) - USD ($)
$ in Millions
9 Months Ended 12 Months Ended
Jun. 30, 2024
Sep. 30, 2023
Common Stock, Large Cap US Companies | Mutual Fund Investments, Concentration Risk | Investment Benchmark    
Liability Class:    
Investment concentration risk (as a percent) 30.00% 25.00%
Common Stock of Small to Mid Cap US Companies | Mutual Fund Investments, Concentration Risk | Investment Benchmark    
Liability Class:    
Investment concentration risk (as a percent) 5.00% 5.00%
Common Stock, International Companies | Mutual Fund Investments, Concentration Risk | Investment Benchmark    
Liability Class:    
Investment concentration risk (as a percent) 5.00% 10.00%
Bond Funds | Mutual Fund Investments, Concentration Risk | Investment Benchmark    
Liability Class:    
Investment concentration risk (as a percent) 15.00% 10.00%
Short-Term Investments | Mutual Fund Investments, Concentration Risk | Investment Benchmark    
Liability Class:    
Investment concentration risk (as a percent) 5.00% 5.00%
Blended Funds | Mutual Fund Investments, Concentration Risk | Investment Benchmark    
Liability Class:    
Investment concentration risk (as a percent) 40.00% 45.00%
Fair Value, Measurements, Recurring    
Asset Class:    
Mutual fund investments in a non-qualified savings plan $ 3.1 $ 2.6
Total Assets 3.1 2.7
Liability Class:    
Liabilities related to non-qualified savings plan (3.1) (2.6)
Total Liabilities (4.9) (4.0)
Fair Value, Measurements, Recurring | Derivatives Designated as Hedging Instruments    
Liability Class:    
Derivative liabilities (1.7) (1.4)
Fair Value, Measurements, Recurring | Derivatives Not Designated as Hedging Instrument    
Liability Class:    
Derivative liabilities (0.1)  
Fair Value, Measurements, Recurring | Natural Gas Instruments, Net | Derivatives Not Designated as Hedging Instrument    
Asset Class:    
Derivatives not designated as hedging instruments - natural gas instruments, net   0.1
Fair Value, Measurements, Recurring | Level One    
Asset Class:    
Mutual fund investments in a non-qualified savings plan 3.1 2.6
Total Assets 3.1 2.6
Liability Class:    
Liabilities related to non-qualified savings plan (3.1) (2.6)
Total Liabilities (3.1) (2.6)
Fair Value, Measurements, Recurring | Level One | Derivatives Designated as Hedging Instruments    
Liability Class:    
Derivative liabilities 0.0 0.0
Fair Value, Measurements, Recurring | Level One | Derivatives Not Designated as Hedging Instrument    
Liability Class:    
Derivative liabilities 0.0  
Fair Value, Measurements, Recurring | Level One | Natural Gas Instruments, Net | Derivatives Not Designated as Hedging Instrument    
Asset Class:    
Derivatives not designated as hedging instruments - natural gas instruments, net   0.0
Fair Value, Measurements, Recurring | Level Two    
Asset Class:    
Mutual fund investments in a non-qualified savings plan 0.0 0.0
Total Assets 0.0 0.1
Liability Class:    
Liabilities related to non-qualified savings plan 0.0 0.0
Total Liabilities (1.8) (1.4)
Fair Value, Measurements, Recurring | Level Two | Derivatives Designated as Hedging Instruments    
Liability Class:    
Derivative liabilities (1.7) (1.4)
Fair Value, Measurements, Recurring | Level Two | Derivatives Not Designated as Hedging Instrument    
Liability Class:    
Derivative liabilities (0.1)  
Fair Value, Measurements, Recurring | Level Two | Natural Gas Instruments, Net | Derivatives Not Designated as Hedging Instrument    
Asset Class:    
Derivatives not designated as hedging instruments - natural gas instruments, net   0.1
Fair Value, Measurements, Recurring | Level Three    
Asset Class:    
Mutual fund investments in a non-qualified savings plan 0.0 0.0
Total Assets 0.0 0.0
Liability Class:    
Liabilities related to non-qualified savings plan 0.0 0.0
Total Liabilities 0.0 0.0
Fair Value, Measurements, Recurring | Level Three | Derivatives Designated as Hedging Instruments    
Liability Class:    
Derivative liabilities 0.0 0.0
Fair Value, Measurements, Recurring | Level Three | Derivatives Not Designated as Hedging Instrument    
Liability Class:    
Derivative liabilities $ 0.0  
Fair Value, Measurements, Recurring | Level Three | Natural Gas Instruments, Net | Derivatives Not Designated as Hedging Instrument    
Asset Class:    
Derivatives not designated as hedging instruments - natural gas instruments, net   $ 0.0
v3.24.3
Fair Value Measurements - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2024
Jun. 30, 2023
Sep. 30, 2023
Debt Instrument [Line Items]        
Increase to contingent consideration liability   $ (23.1) $ 0.0  
Fortress        
Debt Instrument [Line Items]        
Increase to contingent consideration liability $ 0.9 $ 23.1    
Senior Notes | 6.75% Senior Notes due December 2027        
Debt Instrument [Line Items]        
Stated interest rate (as a percent) 6.75% 6.75%   6.75%
Fair value of senior notes $ 477.5 $ 477.5   $ 472.5
Senior Notes Due 2027        
Debt Instrument [Line Items]        
Debt fair value amount 500.0 500.0   500.0
Term Loan        
Debt Instrument [Line Items]        
Fair value of credit agreement debt 342.7 342.7   277.1
Aggregate principal amount due at maturity 346.9 346.9   280.3
Fair Value, Measurements, Recurring        
Debt Instrument [Line Items]        
Mutual fund investments in a non-qualified savings plan $ 3.1 $ 3.1   $ 2.6
v3.24.3
Fair Value Measurements - Schedule of Total Contingent Consideration (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2024
Jun. 30, 2023
Sep. 30, 2023
May 05, 2023
Fair Value Disclosures [Abstract]          
Accrued expenses and other current liabilities $ 0.0 $ 0.0   $ 7.3  
Other noncurrent liabilities 6.9 6.9   31.8  
Total contingent consideration 6.9 6.9   $ 39.1  
Business Acquisition [Line Items]          
Increase to contingent consideration liability   (23.1) $ 0.0    
Payments for contingent consideration   9.1 $ 0.0    
Fortress          
Fair Value Disclosures [Abstract]          
Total contingent consideration         $ 28.0
Business Acquisition [Line Items]          
Increase to contingent consideration liability $ 0.9 23.1      
Payments for contingent consideration   $ 9.1      
v3.24.3
Earnings per Share (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Numerator:        
Net (loss) earnings $ (43.6) $ 36.4 $ (157.8) $ 14.5
Less: net earnings allocated to participating securities 0.0 (0.4) (0.2) (0.2)
Net (loss) earnings available to common stockholders, basic (43.6) 36.0 (158.0) 14.3
Net (loss) earnings available to common stockholders, diluted $ (43.6) $ 36.0 $ (158.0) $ 14.3
Denominator (in thousands):        
Weighted-average common shares outstanding, shares for basic earnings per share (in shares) 41,342 41,142 41,284 40,663
Weighted-average awards outstanding (in shares) 0 0 0 0
Shares for diluted earnings per share (in shares) 41,342 41,142 41,284 40,663
Basic net (loss) earnings per common share (in dollars per share) $ (1.05) $ 0.88 $ (3.83) $ 0.35
Diluted net (loss) earnings per common share (in dollars per share) $ (1.05) $ 0.88 $ (3.83) $ 0.35
Participating securities (in shares) 632,000 453,000 698,000 469,000
Stock Options        
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Anti-dilutive weighted options outstanding (in shares) 874,000 1,151,000 1,427,000 1,267,000
v3.24.3
Related Party Transactions (Details) - USD ($)
3 Months Ended 9 Months Ended
Mar. 20, 2024
Dec. 20, 2023
Jun. 30, 2024
Mar. 31, 2024
Dec. 31, 2023
Jun. 30, 2023
Mar. 31, 2023
Dec. 31, 2022
Jun. 30, 2024
Jun. 30, 2023
Sep. 30, 2023
Related Party Transaction [Line Items]                      
Total revenue     $ 202,900,000     $ 207,600,000     $ 908,600,000 $ 971,100,000  
Receivables     92,300,000           92,300,000   $ 129,300,000
Accounts payable     69,400,000           69,400,000   116,800,000
Cash dividends per share (in dollars per share) $ 0.15 $ 0.15   $ 0.15 $ 0.15 $ 0.15 $ 0.15 $ 0.15      
Payments of dividends                 12,700,000 $ 18,700,000  
Koch Minerals & Trading, LLC                      
Related Party Transaction [Line Items]                      
Total revenue     900,000           2,700,000    
Receivables     500,000           500,000   $ 400,000
Accounts payable     $ 0           0    
Payments of dividends                 $ 2,100,000    
v3.24.3
Subsequent Events (Details) - Subsequent Event
$ in Millions
Sep. 03, 2024
USD ($)
acre
Subsequent Event [Line Items]  
Number of acres utilized for production, conservation and preservation 201,000
Number of acres not utilized for production, conservation and preservation 65,000
Water Rights  
Subsequent Event [Line Items]  
Impairment of indefinite lived intangible assets | $ $ 17.6