CLEARWATER PAPER CORP, 10-Q filed on 10/28/2025
Quarterly Report
v3.25.3
Document and Entity Information - shares
 9 Months Ended
Sep. 30, 2025
Oct. 27, 2025
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Amendment Flag false  
Document Period End Date Sep. 30, 2025  
Entity File Number 001-34146  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q3  
Entity Registrant Name CLEARWATER PAPER CORPORATION  
Entity Central Index Key 0001441236  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 20-3594554  
Entity Address, Address Line One 601 West Riverside,  
Entity Address, Address Line Two Suite 1100  
Entity Address, City or Town Spokane,  
Entity Address, State or Province WA  
Entity Address, Postal Zip Code 99201  
Current Fiscal Year End Date --12-31  
Title of 12(b) Security Common Stock, par value $0.0001 per share  
Trading Symbol CLW  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Document Transition Report false  
Entity Common Stock, Shares Outstanding   16,038,337
Local Phone Number 344-5900  
City Area Code 509  
v3.25.3
Condensed Consolidated Balance Sheets - USD ($)
$ in Millions
Sep. 30, 2025
Dec. 31, 2024
Current assets:    
Cash and cash equivalents $ 34.4 $ 79.6
Receivables, Net 161.7 188.7
Inventories 283.2 258.0
Other current assets 8.7 19.1
Total current assets 487.9 545.4
Property, Plant and Equipment, Gross 2,379.5 2,328.4
Accumulated Depreciation and Amortization, Property, Plant, and Equipment (1,363.6) (1,305.4)
Property, Plant and Equipment, Net 1,015.9 1,023.1
Goodwill and intangible assets 2.7 52.9
Other assets, net 54.9 57.9
TOTAL ASSETS 1,561.4 1,679.2
Current liabilities:    
Accounts Payable and Accrued Liabilities, Current 231.7 319.7
Long-Term Debt, Current Maturities 0.6 0.6
Total current liabilities 232.4 320.4
Long-term debt, net 335.5 281.6
Liability for pension and other postretirement employee benefits 51.6 52.5
Deferred Income Tax Liabilities, Net 80.9 89.7
Other Liabilities, Noncurrent 78.2 80.5
Total liabilities 778.5 824.7
Stockholders' equity:    
Preferred Stock, Value, Issued 0.0 0.0
Common Stock, Value, Issued 0.0 0.0
Additional paid-in capital 8.2 11.5
Treasury Stock, Value (14.8) (3.3)
Retained earnings 823.9 880.8
Accumulated other comprehensive loss, net of tax (34.3) (34.5)
Total stockholders' equity 783.0 854.6
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY $ 1,561.4 $ 1,679.2
v3.25.3
Condensed Consolidated Balance Sheets (Parenthetical)
Sep. 30, 2025
$ / shares
shares
Statement of Financial Position [Abstract]  
Preferred stock, par value (in dollars per share) | $ / shares $ 0.0001
Preferred Stock, Shares Authorized 5,000,000
Preferred stock, shares issued (in shares) 0
Common stock, par value (in dollars per share) | $ / shares $ 0.0001
Common stock, authorized (in shares) 100,000,000
Common stock, shares issued (in shares) 16,567,722
Treasury Stock, Common, Shares 529,385
v3.25.3
Condensed Consolidated Statements of Operations - USD ($)
shares in Thousands, $ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Income Statement [Abstract]        
Net Sales $ 399.0 $ 393.3 $ 1,169.0 $ 996.5
Costs and expenses:        
Cost of sales 380.3 363.2 1,070.6 935.1
Selling, General and Administrative Expense 24.7 31.6 79.7 90.0
Other operating charges, net 1.5 (0.3) 20.4 20.3
Goodwill, Impairment Loss 48.0 0.0 48.0 0.0
Total operating costs and expenses 454.4 394.5 1,218.7 1,045.4
Loss from continuing operations (55.4) (1.2) (49.6) (48.9)
Interest Expense, Net (4.7) (13.1) (12.0) (24.0)
Other Nonoperating Income (Expense) (0.3) 0.3 (0.9) 1.0
Total non-operating expense (5.0) (12.8) (12.9) (22.9)
Loss from continuing operations before income taxes (60.4) (14.0) (62.6) (71.8)
Income tax benefit (6.5) (3.3) (6.3) (17.4)
Income (Loss) from Continuing Operations, Net of Tax (53.9) (10.7) (56.2) (54.4)
Income (Loss) from discontinued operations, net of tax 0.6 16.6 (0.7) 51.6
Net Income (loss) $ (53.3) $ 5.8 $ (56.9) $ (2.8)
Net income (loss) per common share (basic and diluted):        
Income (Loss) from Continuing Operations, Per Basic Share $ (3.34) $ (0.64) $ (3.47) $ (3.27)
Income (Loss) from Continuing Operations, Per Diluted Share (3.34) (0.64) (3.47) (3.27)
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share 0.04 1.00 (0.04) 3.10
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share 0.04 1.00 (0.04) 3.10
Basic (in dollars per share) (3.30) 0.35 (3.51) (0.17)
Diluted (in dollars per share) $ (3.30) $ 0.35 $ (3.51) $ (0.17)
Weighted Average Number of Shares Outstanding, Basic 16,142 16,620 16,213 16,629
v3.25.3
Condensed Consolidated Statements of Comprehensive Income - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Statement of Comprehensive Income [Abstract]        
Net income (loss) $ (53.3) $ 5.8 $ (56.9) $ (2.8)
Defined benefit pension and other postretirement employee benefits:        
Amortization of actuarial gain (loss) included in net periodic cost, net of immaterial tax 0.0 0.0 0.1 (0.1)
Other comprehensive income (loss), net of tax 0.0 0.0 0.1 (0.1)
Comprehensive income (loss) $ (53.3) $ 5.8 $ (56.8) $ (2.9)
v3.25.3
Condensed Consolidated Statements of Cash Flows - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2025
Mar. 31, 2025
Sep. 30, 2024
Mar. 31, 2024
Sep. 30, 2025
Sep. 30, 2024
Dec. 31, 2024
CASH FLOWS FROM OPERATING ACTIVITIES              
Net income (loss) $ (53.3) $ (6.3) $ 5.8 $ 17.2 $ (56.9) $ (2.8)  
Goodwill, Impairment Loss 48.0   0.0   48.0 0.0  
Depreciation and amortization         68.7 78.3  
Equity-based compensation expense 0.6   (0.9)   4.1 7.2  
Deferred Income Taxes and Tax Credits         (7.0) (10.0)  
Defined benefit pension and other postretirement employee benefits         (0.3) (3.2)  
Gain (Loss) on Disposition of Business (1.1)   0.0   (1.1) 0.0  
Amortization of Debt Issuance Costs and Discounts         1.7 2.0  
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property         (5.1) (1.6)  
(Increase) decrease in accounts receivable         26.8 (62.3)  
Increase in inventories         (25.3) (5.6)  
Decrease in other current assets         9.9 3.4  
Increase (decrease) in accounts payable and accrued liabilities         (65.0) 89.8  
Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Other Item         (1.4) (1.9)  
Net cash flows provided by operating activities         7.3 96.5  
CASH FLOWS FROM INVESTING ACTIVITIES              
Additions to property, plant and equipment, net 1         (73.9) (83.6)  
Payments to Acquire Businesses, Gross         0.0 (708.2)  
Proceeds from Divestiture of Businesses         (12.1) 0.0  
Net cash flows used in investing activities         (86.0) (791.8)  
CASH FLOWS FROM FINANCING ACTIVITIES              
Proceeds from Issuance of Long-Term Debt         72.0 753.5  
Repayments of Long-term Debt         (18.5) (50.9)  
Payments for Repurchase of Common Stock         (17.2) (6.0)  
Payments of Debt Issuance Costs         0.0 (4.9)  
Proceeds from (Payment for) Other Financing Activity         (2.8) (2.7)  
Net cash flows provided by financing activities         33.5 688.9  
Decrease in cash and cash equivalents         (45.2) (6.5)  
Cash and cash equivalents at beginning of period   $ 79.6   $ 42.0 79.6 42.0 $ 42.0
Cash and cash equivalents at end of period $ 34.4   $ 35.5   34.4 35.5 79.6
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:              
Cash paid for interest, net of amounts capitalized         14.8 42.7  
Income Taxes Paid         57.4 14.8  
Capital Expenditures Incurred but Not yet Paid         $ 11.8 [1] $ 25.5 [1] $ 25.8
[1] Capital expenditures of $11.8 million and $25.5 million that have not been paid as of September 30, 2025 and 2024 were excluded from the Statements of Cash Flows.
v3.25.3
Consolidated Statements of Stockholder's Equity Consolidated Statements of Stockholder's Equity - USD ($)
$ in Millions
Total
Common Stock
Additional Paid-In Capital
Retained Earnings
Accumulated Other Comprehensive Loss
Treasury Stock, Common
Common Stock, Value, Issued $ 0.0          
Beginning balance (in shares) at Dec. 31, 2023   16,485,000        
Beginning balance at Dec. 31, 2023 668.8   $ 14.9 $ 684.5 $ (30.7)  
Net income 17.2     17.2    
Stock-based compensation expense 2.2   2.2      
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture   175,000        
Issuance of shares under stock plans, net (3.1)   (3.1)      
Stock Repurchased and Retired During Period, Shares   (13,000)        
Stock Repurchased and Retired During Period, Value (0.5)   (0.5)      
Ending balance (in shares) at Mar. 31, 2024   16,647,000        
Ending balance at Mar. 31, 2024 684.5   13.5 701.7 (30.7)  
Beginning balance (in shares) at Dec. 31, 2023   16,485,000        
Beginning balance at Dec. 31, 2023 668.8   14.9 684.5 (30.7)  
Net income (2.8)          
Ending balance (in shares) at Sep. 30, 2024   16,591,000        
Ending balance at Sep. 30, 2024 $ 664.6 $ 0.0 13.7 681.7 (30.8)  
Treasury Stock, Common, Shares 0          
Treasury Stock, Value $ 0.0          
Common Stock, Value, Issued 0.0          
Beginning balance (in shares) at Mar. 31, 2024   16,647,000        
Beginning balance at Mar. 31, 2024 684.5   13.5 701.7 (30.7)  
Net income (25.8)     (25.8)    
Stock-based compensation expense 2.8   2.8      
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture   59,000        
Issuance of shares under stock plans, net $ 0.2   0.2      
Stock Repurchased and Retired During Period, Shares (64,000)          
Stock Repurchased and Retired During Period, Value $ (3.0)   (3.0)      
Ending balance (in shares) at Jun. 30, 2024   16,642,000        
Ending balance at Jun. 30, 2024 $ 658.6   13.5 675.8 (30.7)  
Treasury Stock, Common, Shares 0          
Treasury Stock, Value $ 0.0          
Common Stock, Value, Issued   $ 0.0        
Net income 5.8     5.8    
Stock-based compensation expense 2.7   2.7      
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture   13,000        
Issuance of shares under stock plans, net $ 0.1   0.1      
Stock Repurchased and Retired During Period, Shares (64,000)          
Stock Repurchased and Retired During Period, Value $ (2.5)   (2.5)      
Ending balance (in shares) at Sep. 30, 2024   16,591,000        
Ending balance at Sep. 30, 2024 $ 664.6 $ 0.0 13.7 681.7 (30.8)  
Treasury Stock, Common, Shares (122,821)          
Treasury Stock, Value $ (3.3)          
Common Stock, Value, Issued 0.0          
Beginning balance (in shares) at Dec. 31, 2024   16,568,000        
Beginning balance at Dec. 31, 2024 854.6   11.5 880.8 (34.5)  
Net income (6.3)     (6.3)    
Stock-based compensation expense $ 1.4   1.4      
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture 191,000 0        
Issuance of shares under stock plans, net $ (2.3)   (7.9)     $ (5.7)
Treasury Stock, Value, Acquired, Cost Method $ (10.9)          
Treasury Stock, Value, Acquired, Cost Method (380,000)          
Stock Repurchased and Retired During Period, Value $ (10.9)   0.0      
Ending balance (in shares) at Mar. 31, 2025   16,568,000        
Ending balance at Mar. 31, 2025 836.6   5.0 874.5 (34.5)  
Beginning balance (in shares) at Dec. 31, 2024   16,568,000        
Beginning balance at Dec. 31, 2024 854.6   11.5 880.8 (34.5)  
Net income (56.9)          
Ending balance (in shares) at Sep. 30, 2025   16,568,000        
Ending balance at Sep. 30, 2025 $ 783.0 $ 0.0 8.2 823.9 (34.3)  
Treasury Stock, Common, Shares (312,000)          
Treasury Stock, Value $ (8.5)          
Common Stock, Value, Issued   $ 0.0        
Beginning balance (in shares) at Mar. 31, 2025   16,568,000        
Beginning balance at Mar. 31, 2025 836.6   5.0 874.5 (34.5)  
Net income 2.7     2.7    
Stock-based compensation expense $ 1.6   1.6      
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture 2,000 0        
Issuance of shares under stock plans, net $ 0.0   (0.1)     $ 0.0
Treasury Stock, Value, Acquired, Cost Method $ (4.2)          
Treasury Stock, Value, Acquired, Cost Method (148,000)          
Stock Repurchased and Retired During Period, Value $ (4.2)   0.0      
Ending balance (in shares) at Jun. 30, 2025   16,568,000        
Ending balance at Jun. 30, 2025 836.8   6.5 877.3 (34.4)  
Pension and other postretirement employee benefit plans, net of tax $ 0.1       0.1  
Treasury Stock, Common, Shares (459,000)          
Treasury Stock, Value $ (12.7)          
Common Stock, Value, Issued   $ 0.0        
Net income (53.3)     (53.3)    
Stock-based compensation expense 1.6   1.6      
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture   0        
Issuance of shares under stock plans, net 0.0   0.0      
Treasury Stock, Value, Acquired, Cost Method $ (2.1)          
Treasury Stock, Value, Acquired, Cost Method (71,000)          
Stock Repurchased and Retired During Period, Shares   0        
Stock Repurchased and Retired During Period, Value $ (2.1)   0.0      
Ending balance (in shares) at Sep. 30, 2025   16,568,000        
Ending balance at Sep. 30, 2025 783.0 $ 0.0 $ 8.2 $ 823.9 (34.3)  
Pension and other postretirement employee benefit plans, net of tax $ 0.1       $ 0.1  
Treasury Stock, Common, Shares (529,385)          
Treasury Stock, Value $ (14.8)          
Common Stock, Value, Issued $ 0.0          
v3.25.3
Basis of Presentation
 9 Months Ended
Sep. 30, 2025
Accounting Policies [Abstract]  
Nature of Operations and Basis of Presentation Description of Business and Basis of Presentation
Description of Business
We are a premier manufacturer and supplier of bleached paperboard focused on servicing independent converters in North America. We also offer services that include custom sheeting, slitting, and cutting.
During the year ended December 31, 2024, we sold our tissue (consumer products) operations. Accordingly, the results of our previously-owned tissue operations have been presented as discontinued operations in our Consolidated Statements of Operations for all periods presented. See Note 4, "Discontinued operations."
Basis of Presentation
The accompanying unaudited Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United States (U.S. GAAP) for interim financial information. Accordingly, they do not include all the information and footnotes required by U.S. GAAP for complete consolidated financial statements. In the opinion of management, all adjustments considered necessary for a fair presentation have been included and are of a normal and recurring nature. These consolidated financial statements and related Notes should be read in conjunction with our annual report on Form 10-K for the fiscal year ended December 31, 2024. Results of operations for interim periods are not necessarily indicative of results to be expected for an entire year. All dollar amounts are shown in millions, except per share amounts.
v3.25.3
Recently Adopted and New Accounting Standards New Accounting Pronouncements (Notes)
 9 Months Ended
Sep. 30, 2025
Accounting Standards Update and Change in Accounting Principle [Abstract]  
New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Recently Issued Accounting Standards
In July 2025, the FASB issued ASU 2025-05, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets, which provides a practical expedient permitting entities to assume that conditions at the balance sheet date remain unchanged over the life of the asset when estimating expected credit losses for current accounts receivable. This ASU is effective or annual reporting periods beginning after December 15, 2025, and for interim periods within those annual reporting periods, with early adoption permitted. We are currently evaluating the impact this ASU will have on our consolidated financial statements.
In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses (Subtopic 220-40), which requires disaggregated disclosure of certain types of expenses, such as inventory purchases, employee compensation, depreciation, and amortization in commonly presented expense captions such as cost of revenue and selling, general and administrative expenses. This ASU is effective for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. Adoption of this ASU will result in additional disclosure, but it will not impact our consolidated financial position, results of operations or cash flows.
In December 2023, the FASB issued ASU No. 2023-09, Income Taxes—Improvements to Income Tax Disclosures (Topic 740), which requires enhanced disclosures primarily related to the rate reconciliation and disaggregation of income taxes paid. This ASU is effective for annual periods beginning after December 15, 2024, with early adoption permitted. We will adopt this ASU prospectively and it will result in additional disclosure, but it will not impact our consolidated financial position, results of operations or cash flows.
v3.25.3
Business Combinations and Asset Acquisitions
 9 Months Ended
Sep. 30, 2025
Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract]  
Business Combination Business Acquisition
On May 1, 2024, we completed the acquisition of a paperboard manufacturing facility and associated business, located in Augusta, Georgia (Augusta). The purchase price of the Augusta acquisition was allocated to assets acquired and liabilities based on the fair values as of the date of acquisition. The purchase price allocation was final as of May 1, 2025.
The purchase price allocation as of May 1, 2025 is as follows:
May 1, 2024
Original Purchase Price AllocationMeasurement Period AdjustmentsFinal Purchase Price Allocation
Purchase price$708.2 $— $708.2 
Inventories, net102.8 0.7 103.5 
Other current assets0.4 (0.1)0.4 
Property, plant and equipment609.3 1.0 610.3 
Other assets, net11.8 — 11.8 
Total assets acquired724.3 1.6 725.9 
Current portion of long-term debt(0.6)— (0.6)
Accounts payable and accrued liabilities(7.7)(0.8)(8.5)
Long-term debt(8.9)— (8.9)
Other long-term obligations(12.6)— (12.6)
Total liabilities assumed(29.7)(0.8)(30.5)
Net assets acquired694.5 0.8 695.3 
Goodwill13.7 (0.8)12.9 
Total estimated fair value of net assets acquired$708.2 $— $708.2 
The following unaudited pro forma consolidated financial information combines our results and the unaudited results of the Augusta operations had the transaction been completed on January 1, 2024. In addition, these results are not intended to be a projection of future results and do not reflect events that may occur after the Augusta acquisition, including but not limited to revenue enhancements, cost savings or operating synergies that we may achieve as a result of the Augusta acquisition.
Nine Months Ended September 30,
2024
Net sales$1,185.3 
Net income (loss)(16.1)
v3.25.3
Discontinued Operations and Disposal Groups
 9 Months Ended
Sep. 30, 2025
Discontinued Operations and Disposal Groups [Abstract]  
Disposal Groups, Including Discontinued Operations, Disclosure Discontinued Operations
In November 2024, we sold our tissue operations. The results of our tissue operations were classified as discontinued operations in our Consolidated Statements of Operations for all periods presented. Amounts included below, for the quarter and nine months ended September 30, 2025, consist of the settlement of contractual and employment related obligations that are directly related to the disposal. The following table presents the financial results of the tissue segment for the quarter and nine months ended September 30, 2025 and 2024:
 Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Net sales$— $262.4 $— $768.3 
Cost of sales0.1 212.2 1.0 611.1 
Selling, general and administrative expenses0.1 7.0 0.3 22.7 
Depreciation and amortization— 6.7 — 35.0 
Gain on business divestiture(1.1)— (1.1)— 
Other operating charges, net0.1 6.3 1.6 10.8 
Income (loss) from discontinued operations0.8 30.1 (1.8)88.7 
Other non-operating expense— (8.0)— (19.7)
   Total non-operating expense— (8.0)— (19.7)
Income (loss) from discontinued operations before income taxes0.8 22.1 (1.8)68.9 
Income tax provision (benefit)0.2 5.6 (1.2)17.4 
Income (loss) from discontinued operations, net of tax$0.6 $16.6 $(0.7)$51.6 
The major components of “Other operating charges, net” included in discontinued operations for the quarter and nine months ended September 30, 2025 and 2024 are reflected in the table below.
Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Divestiture related costs$0.1 $6.2 $1.6 $10.5 
Loss on sale or impairment associated with assets— 0.1 — 0.3 
$0.1 $6.3 $1.6 $10.8 
During the quarter ended September 30, 2025, we finalized the working capital adjustment associated with the business divestiture, resulting in a $1.1 million gain due to the reversal of a portion of the previously accrued settlement amount. The final cash payment totaled $12.1 million.
Operating and investing cash flows of the discontinued operation are presented in the following table:
 Nine Months Ended September 30,
20252024
Net cash provided by (used in) operating activities of discontinued operations$(1.4)$133.8 
Net cash used in investing activities of discontinued operations— (9.8)
v3.25.3
Fair Value Measures and Disclosures
 9 Months Ended
Sep. 30, 2025
Fair Value Disclosures [Abstract]  
Fair Value Disclosures Fair Value Measurements
Carrying amounts reported on the consolidated balance sheets for cash and cash equivalents, accounts receivable and accounts payable approximate fair value due to the short-term maturity of these instruments. The fair value of our debt is included in the following table:
September 30, 2025December 31, 2024
2020 Notes, maturing 2028, fixed interest rate$257.8 $258.9 
ABL Credit Agreement, variable interest rate54.0 — 
$311.8 $258.9 
v3.25.3
Receivables, net (Notes)
 9 Months Ended
Sep. 30, 2025
Receivables, Net, Current [Abstract]  
Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Receivables
Receivables consist of:
September 30, 2025December 31, 2024
Trade accounts receivable$144.3 $167.5 
Allowance for current expected credit losses(1.8)(1.6)
Unbilled receivables5.4 5.3 
Taxes receivable8.4 2.6 
Other5.3 15.0 
$161.7 $188.7 
v3.25.3
Inventories
 9 Months Ended
Sep. 30, 2025
Inventory Disclosure [Abstract]  
Inventories Inventories
Inventories are stated at the lower of net realizable value or current cost using the average cost method and consist of:
September 30, 2025December 31, 2024
Logs, chips and sawdust$27.5 $25.1 
Pulp8.4 6.9 
Paperboard products136.9 123.4 
Materials and supplies110.4 102.5 
$283.2 $258.0 
v3.25.3
Property, Plant, and Equipment
 9 Months Ended
Sep. 30, 2025
Property, Plant and Equipment [Abstract]  
Property, Plant and Equipment Disclosure Property, Plant and Equipment
Property, plant and equipment consist of:
September 30, 2025December 31, 2024
Land and land improvements$65.7 $65.8 
Buildings and improvements232.6 232.4 
Machinery and equipment2,028.9 1,942.6 
Construction in progress52.3 87.6 
2,379.5 2,328.4 
Less accumulated depreciation and amortization(1,363.6)(1,305.4)
Property, plant and equipment, net$1,015.9 $1,023.1 
v3.25.3
Intangible Assets, Goodwill and Other
 9 Months Ended
Sep. 30, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill and Intangible Assets Disclosure Goodwill and Intangibles
Changes in the carrying amounts of goodwill and intangible assets are as follows:
GoodwillIntangiblesTotal
Balance as of December 31, 2024
$48.6 $4.3 $52.9 
Recognized goodwill - measurement period adjustment(0.7)— (0.7)
Goodwill impairment(48.0)— (48.0)
  Amortization— (1.6)(1.6)
Balance as of September 30, 2025
$— $2.7 $2.7 

During the third quarter of 2025, we concluded that the sustained decline in our stock price (market capitalization) was a triggering event requiring an interim goodwill impairment assessment. We accumulated $35.1 million of goodwill through the acquisition of Manchester Industries in 2016 and $12.9 million of goodwill through the acquisition of the Augusta paperboard facility in 2024. Based on our interim goodwill impairment assessment, we concluded that our carrying value exceeded the estimated fair value. As a result, we have recorded a non-cash goodwill impairment charge of $48.0 million in the third quarter of 2025 which represents a full impairment of the goodwill. The decline in the estimated fair value and the resulting impairment was primarily driven by continued paperboard market softness and additional market capacity coming online which drove a sustained decline in our market capitalization. This was coupled with the increase in our carrying
value related to the divestiture of our tissue business in late 2024. The fair market value considered both the market and income approach. As a result of the triggering event, we conducted a recoverability analysis on other long-term assets, including fixed assets and intangible assets subject to amortization. The results indicated that there was no need for any further impairment charges.
v3.25.3
Payables and Accruals
 9 Months Ended
Sep. 30, 2025
Payables and Accruals [Abstract]  
Accounts Payable and Accrued Liabilities Disclosure Accounts Payable and Accrued Liabilities
Accounts payable and accrued liabilities consist of:
September 30, 2025December 31, 2024
Trade payables$145.7 $164.6 
Accrued compensation31.6 38.2 
Operating lease liabilities11.8 11.1 
Taxes payable— 50.8 
Accrued discounts12.1 8.9 
Other30.5 46.1 
$231.7 $319.7 
Included in "Accounts payable and accrued liabilities" are $11.8 million and $25.8 million related to capital expenditures that had not yet been paid as of September 30, 2025 and December 31, 2024.
We maintain a program with a financial institution to provide our vendors with an option to receive payment earlier than our standard payment terms. As of September 30, 2025 and December 31, 2024, $6.3 million and $12.7 million of outstanding obligations under this program were included in "Other" in the table above.
v3.25.3
Income Taxes
 9 Months Ended
Sep. 30, 2025
Income Tax Disclosure [Abstract]  
Taxes Income Taxes
For interim periods, accounting standards require that income tax expense be determined by applying the estimated annual effective income tax rate to year-to-date results, unless this method does not result in a reliable estimate of year-to-date income tax expense. Each period, the income tax accrual is adjusted to the latest estimate and the difference from the previously accrued year-to-date balance is adjusted to the current quarter.
For the nine months ended September 30, 2025 and 2024, we recognized an income tax benefit of $6.3 million and $17.4 million on loss from continuing operations. Our effective tax rate for the nine months ended September 30, 2025 varied from the U.S. federal statutory tax rate of 21% primarily due to the effects of state taxes, effects of the tax basis of our goodwill impairment and a change in the state valuation allowance.
v3.25.3
Debt
 9 Months Ended
Sep. 30, 2025
Debt Disclosure [Abstract]  
Debt Disclosure Debt
Long-term debt at the balance sheet dates consisted of:
September 30, 2025December 31, 2024
Interest Rate at September 30, 2025PrincipalUnamortized Debt CostsTotalPrincipalUnamortized Debt CostsTotal
2020 Notes, maturing 2028, fixed interest rate4.75%$275.0 $(1.5)$273.5 $275.0 $(1.8)$273.2 
ABL Credit Agreement (revolving loan), maturing 2027, variable interest rate5.49%54.0 — 54.0 — — — 
Finance leases8.6 — 8.6 9.1 — 9.1 
Total debt337.6 (1.5)336.1 284.1 (1.8)282.2 
Less: current portion(0.6)— (0.6)(0.6)— (0.6)
Net long-term portion$337.0 $(1.5)$335.5 $283.4 $(1.8)$281.6 
PCA CREDIT AGREEMENT
On May 1, 2024, we entered into the PCA Credit Agreement with the lenders party thereto and AgWest Farm Credit, PCA, as administrative agent. The PCA Credit Agreement amended and restated our prior credit agreement dated as of October 27, 2023 with the lenders party thereto and AgWest Farm Credit, PCA as administrative agent. The term revolver
commitment under the PCA Credit Agreement is subject to an annual reduction of 2% of the commitments then in effect and is currently $264.6 million. As of September 30, 2025, no balance was outstanding on the term revolver commitment. We may increase term revolver commitments under the PCA Credit Agreement in an aggregate amount of up to $60.0 million, subject to obtaining commitments from any participating lenders and certain other conditions. The PCA Credit Agreement matures on May 1, 2029, subject to a springing maturity 91 days prior to the maturity of the Company’s 2020 Notes if the outstanding principal of the 2020 Notes plus $50.0 million at any time during such 91 day period is greater than the sum of our available borrowing liquidity and unrestricted cash.
We may prepay and reborrow any borrowings under the PCA Credit Agreement, in whole or in part, at any time and from time to time without premium or penalty (except in certain circumstances). In addition, we must make mandatory prepayments of principal under the PCA Credit Agreement upon the occurrence of certain asset sales.
ABL CREDIT AGREEMENT
Our ABL Credit Agreement matures on November 7, 2027. The revolving loan commitment under the ABL Credit Agreement is $375.0 million, subject to borrowing base limitations based on a percentage of applicable eligible receivables and eligible inventory. As of September 30, 2025, our eligible receivables and inventory supported up to $213.9 million availability under the line, of which we utilized $57.7 million, consisting of $54.0 million borrowings outstanding and $3.7 million to issue letters of credit.
We may, at our option, prepay any borrowings under the ABL Credit Agreement, in whole or in part, at any time and from time to time without premium or penalty (except in certain circumstances). We may also increase the revolving commitments under the ABL Credit Agreement in an aggregate amount of up to $100 million, subject to obtaining commitments from any participating lenders and certain other conditions.
v3.25.3
Other Operating Charges, net (Notes)
 9 Months Ended
Sep. 30, 2025
Other Income and Expenses [Abstract]  
Other Operating Income and Expense Other Operating Charges
The major components of “Other operating charges, net” in the Consolidated Statements of Operations for the quarter and nine months ended September 30, 2025 and 2024 are reflected in the table below and described in the paragraphs following the table. These items are considered outside of our core operations.
Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Acquisition related costs$— $0.5 $— $13.9 
Integration costs0.5 2.3 5.2 5.7 
Cost reduction plan— — 6.1 — 
Loss on sale or impairment associated with assets1.9 0.4 5.1 1.1 
Directors' equity-based compensation expense(1.0)(3.5)(0.5)(0.4)
Other— — 4.5 — 
$1.5 $(0.3)$20.4 $20.3 
During the third quarter of 2025, we recorded $1.5 million of expense in "Other operating charges, net." The main components of the expense include:
•expense of $0.5 million associated with integration activities related to the Augusta operations;
•loss of $1.9 million associated with impairment of assets; and
•reversal of expense of $1 million relating to directors' equity-based compensation which is remeasured each period based upon changes in our stock price.
During the third quarter of 2024, we recorded $0.3 million of income in "Other operating charges, net." The components of the income include:
•expense of $0.5 million associated with acquisition activities (primarily legal and professional services);
•expense of $2.3 million associated with integration activities (primarily professional services);
•loss of $0.4 million associated with the impairment of property, plant and equipment; and
•reversal of expense of $3.5 million relating to directors' equity-based compensation which is remeasured each period based upon changes in our stock price.
During the nine months ended September 30, 2025, we recorded $20.4 million of expense in "Other operating charges, net." The main components of the expense include:
•expense of $5.2 million associated with integration activities related to the Augusta operations;
•expense of $6.1 million associated with our cost reduction plan (primarily severance cost);
•loss of $5.1 million associated with impairment of assets; and
•reversal of expense of $0.5 million relating to directors' equity-based compensation which is remeasured each period based upon changes in our stock price.
During the nine months ended September 30, 2024, we recorded $20.3 million of expense in "Other operating charges, net." The main components of the expense include:
•expense of $13.9 million associated with integration activities related to the Augusta operations;
•expense of $5.7 million associated with restructuring and integration activities (primarily professional services);
•loss of $1.1 million associated with impairment of assets; and
•reversal of expense of $0.4 million relating to directors' equity-based compensation which is remeasured each period based upon changes in our stock price.
v3.25.3
Non-operating Income (Expense) (Notes)
 9 Months Ended
Sep. 30, 2025
Nonoperating Income (Expense) [Abstract]  
Other Nonoperating Income and Expense [Text Block] Non-Operating Expense
The components of “Non-operating expense” in the Consolidated Statements of Operations for the quarter and nine months ended September 30, 2025 and 2024 are reflected in the table below:
Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Interest expense$(4.5)$(13.0)$(11.8)$(24.6)
Amortization of debt issuance costs(0.6)(0.6)(1.7)(1.2)
Interest income0.3 0.4 1.4 1.8 
Interest expense, net(4.7)(13.1)(12.0)(24.0)
Non-operating pension and other postretirement employee benefits(0.3)0.3 (0.9)1.0 
Total non-operating expense$(5.0)$(12.8)$(12.9)$(22.9)
v3.25.3
Retirement Plans and Postretirement Benefits
 9 Months Ended
Sep. 30, 2025
Postemployment Benefits [Abstract]  
Pension and Other Postretirement Employee Benefit Plans Retirement Plans and Postretirement Benefits
The following table details the components of net periodic cost of our company-sponsored pension and other postretirement employee benefit plans for the periods presented:
 Quarter Ended September 30,Nine Months Ended September 30,
Pension Benefit Plans2025202420252024
Service cost$0.8 $0.6 $2.3 $1.9 
Interest cost3.0 3.0 8.9 8.9 
Expected return on plan assets(3.3)(3.9)(10.0)(11.8)
Amortization of actuarial loss0.2 — 0.6 0.1 
Net periodic cost $0.6 $(0.3)$1.7 $(0.9)

 Quarter Ended September 30,Nine Months Ended September 30,
Other Postretirement Employee Benefit Plans2025202420252024
Service cost$— $0.1 $0.1 $0.2 
Interest cost0.6 0.7 1.9 2.0 
Amortization of actuarial gain(0.1)(0.1)(0.4)(0.2)
Net periodic cost$0.5 $0.6 $1.6 $2.0 

We record the service component of net periodic cost as part of "Cost of sales" and "Selling, general, and administrative expenses," while the non-service component of net periodic cost is recorded in "Other non-operating income (expense)" on our Consolidated Statements of Operations. For the quarter and nine months ended September 30, 2025, we recorded $0.6 million and $2.0 million to "Cost of sales" and $0.2 million and $0.4 million to "Selling, general, and administrative
expenses". For the quarter and nine months ended September 30, 2024, we recorded $0.6 million and $1.7 million to "Cost of sales", $0.1 million and $0.4 million to "Selling, general, and administrative expenses", and $0.1 million and $0.2 million to Discontinued Operations.
v3.25.3
Accumulated Other Comprehensive Loss (Notes)
 9 Months Ended
Sep. 30, 2025
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]  
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Accumulated Other Comprehensive Loss
Accumulated other comprehensive loss, net of tax, is comprised of the following:
Pension Plan AdjustmentsOther Post Retirement Employee Benefit Plan AdjustmentsTotal
Balance at December 31, 2023$(42.0)$11.3 $(30.7)
Amounts reclassified from accumulated other comprehensive loss0.1 (0.2)(0.1)
Balance at September 30, 2024$(41.9)$11.1 $(30.8)
Balance at December 31, 2024$(47.8)$13.4 $(34.5)
Amounts reclassified from accumulated other comprehensive loss0.4 (0.3)0.1 
Balance at September 30, 2025$(47.4)$13.1 $(34.3)
v3.25.3
Stockholders' Equity
 9 Months Ended
Sep. 30, 2025
Share-Based Payment Arrangement [Abstract]  
Equity Stockholders' Equity
Common Stock Plans
We have stock-based compensation plans under which restricted stock awards and stock options are outstanding or granted subject to time or performance vesting requirements. At September 30, 2025, approximately 0.6 million shares were available for future issuance under our current plan.
Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Total stock-based compensation expense (income)$0.6 $(0.9)$4.1 $7.2 
Income tax provision (benefit) related to stock-based compensation$— $(0.5)$0.2 $0.8 
Impact on cash flow from proceeds on options exercised$— $0.2 $— $1.3 
Impact on cash flow due to taxes paid related to net share settlement of equity awards$— $0.1 $2.3 $4.1 
As of September 30, 2025, there was $10.8 million of total unrecognized compensation costs related to outstanding restricted stock unit awards.
During the nine months ended September 30, 2025, we granted 198,887 restricted stock units (time vesting) at an average grant date fair value of $28.36 per share and 194,378 restricted stock units (performance vesting) at an average grant date fair value of $31.04 per share.
During the quarter and nine months ended September 30, 2024, stock-based compensation income of $1.3 million and expense of $6.0 million was charged to continuing operations, and expense of $0.4 million and $1.2 million was charged to discontinued operations.
v3.25.3
Earnings per Common Share
 9 Months Ended
Sep. 30, 2025
Earnings Per Share [Abstract]  
Earnings per Common Share Loss) per Share
Basic income (loss) per share is based on the weighted-average number of shares of common stock outstanding. Diluted income (loss) per share is based upon the weighted-average number of shares of common stock outstanding plus all potentially dilutive securities that were assumed to be converted into common shares at the beginning of the period under the treasury stock method. This method requires the effect of potentially dilutive common stock equivalents be excluded from the calculation of diluted earnings per share for the periods in which net losses from continuing operations are reported because the effect is anti-dilutive.
Shares excluded from the computation of diluted earnings (loss) per share were 0.3 million for the quarter and nine months ended September 30, 2025 and 0.3 million and 0.4 million for the quarter and nine months ended September 30, 2024 due to our loss position on continuing operations in both periods presented.
v3.25.3
Restructuring and Related Activities
 9 Months Ended
Sep. 30, 2025
Restructuring and Related Activities [Abstract]  
Restructuring and Related Activities Disclosure Cost Reduction Plan
In early 2025, we announced a plan to reduce our cost structure across operations and selling, general and administrative expenses as we right-size our operations after the sale of our tissue operations (discussed at Note 4). In connection with these activities, we expect to record employee severance costs of $5 to $7 million by the end of 2025. During the quarter, we recorded a reversal of severance expense of $0.1 million and during the nine months ended September 30, 2025, we recorded expense of $5.0 million associated with this plan. The remaining severance will be recognized from the date of notification until it is earned.
Changes in our severance liability (included in accounts payable and accrued liabilities on the consolidated balance sheet) for the nine months ended September 30, 2025 are as follows:
 Total
Balance at December 31, 2024$— 
Employee severance charges included in "other operating charges, net"5.0 
Cost paid or otherwise settled(4.6)
Balance at September 30, 2025$0.4 
v3.25.3
Segment Reporting
 9 Months Ended
Sep. 30, 2025
Segment Reporting [Abstract]  
Segment Reporting Disclosure Segment Disclosure
Our Chief Operating Decision Maker (CODM) evaluates performance and makes operating decisions about allocating resources based on financial data presented on a consolidated basis. Since our CODM evaluates financial performance on a consolidated basis, we have determined that we have a single operating segment composed of the consolidated financial results of Clearwater Paper.
Our CODM also reviews total assets, as reported on our consolidated balance sheets, and purchases of property and equipment, as reported on our consolidated statements of cash flows.
Our CODM utilizes other key operating metrics, including disaggregated measures of net sales by product line, disaggregation of significant segment expenses and Adjusted EBITDA in order to assess our financial performance.
Net sales classified by major product lines and a reconciliation of significant expenses to consolidated income from continuing operations is as follows:
Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Net sales by product line:
Food service$182.0 $142.1 $499.3 $366.5 
Folding carton143.0 182.1 438.9 436.7 
Sheeting and distribution37.9 41.6 116.5 123.2 
Pulp and other36.1 27.5 114.4 70.2 
Total net sales$399.0 $393.3 $1,169.0 $996.5 
Input cost (raw materials and energy)173.5 177.2 518.5 438.6 
Labor and overhead142.1 129.4 387.2 344.5 
Supply chain costs (principally freight)40.6 39.5 116.0 101.4 
Selling, general and administrative expenses23.7 30.7 76.6 86.9 
Goodwill impairment charge48.0 — 48.0 — 
Depreciation and amortization23.8 22.4 68.7 48.4 
Interest expense, net4.7 13.1 12.0 24.0 
Non-significant expenses3.0 (5.0)4.6 24.5 
Income tax benefit(6.5)(3.3)(6.3)(17.4)
Loss from continuing operations$(53.9)$(10.7)$(56.2)$(54.4)
Non-significant expenses is primarily made up of other operating charges, net and changes in inventory.
v3.25.3
Unusual or Infrequently Occurring Items
 9 Months Ended
Sep. 30, 2024
Unusual or Infrequent Items, or Both [Abstract]  
Unusual or Infrequent Items, or Both, Disclosure Insurance Recovery
During the first quarter of 2024, we experienced a natural gas disruption due to an extreme weather event that resulted in damage at our Lewiston, Idaho facility. During the quarter ended June 30, 2024, we received $10.5 million in insurance proceeds, of which $4.7 million was related to business interruption insurance and $5.8 million was related to reimbursable costs. We allocated proceeds of $0.9 million to discontinued operations and $9.3 million to continuing operations, and they are recorded within "Cost of sales" in the Consolidated Statement of Operations. Proceeds of $0.3 million were related to property, plant and equipment.
v3.25.3
Insider Trading Arrangements
 3 Months Ended
Sep. 30, 2025
shares
Trading Arrangements, by Individual  
Material Terms of Trading Arrangement
Rule 10b5-1 Trading Arrangements
During the quarter ended September 30, 2025, the following officer (as defined in Rule 16a-1(f) of the Exchange Act) adopted a Rule 10b5-1 trading arrangement, as defined in Item 408 of Regulation S-K, for the sale of our common stock. Shares in the 10b5-1 trading arrangement that are subject to restricted stock units (“RSUs”) and stock options may only be traded following satisfaction of applicable vesting requirements. In addition, because of pricing (such as future share price targets) and timing conditions in the 10b5-1 trading arrangement, it is not yet determinable how many shares actually will be sold under the plan prior to its expiration date.
On August 29, 2025, Steve Bowden, our Senior Vice President, Operations, entered into a Rule 10b5-1 trading arrangement that provides for the sale of up to 8,889 shares of our common stock. This trading arrangement is scheduled to expire on December 31, 2025.
This Rule 10b5-1 trading arrangement was entered into in writing during an open trading window, includes the mandatory cooling-off period and good-faith certification required by Rule 10b5-1(c)(1), and is intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act and our policies regarding transactions in our securities.
During the quarter ended September 30, 2025, none of our other officers or directors adopted or terminated a Rule 10b5-1 arrangement or non-Rule 10b5-1 trading arrangement, as each is defined in Item 408(a) of Regulation S-K.
Name Steve Bowden
Title Senior Vice President
Rule 10b5-1 Arrangement Adopted true
Non-Rule 10b5-1 Arrangement Adopted false
Adoption Date August 29, 2025
Rule 10b5-1 Arrangement Terminated false
Expiration Date December 31, 2025
Aggregate Available 8,889
v3.25.3
Business Combinations and Asset Acquisitions (Tables)
 9 Months Ended
Sep. 30, 2025
Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract]  
Business Combination, Recognized Asset Acquired and Liability Assumed
May 1, 2024
Original Purchase Price AllocationMeasurement Period AdjustmentsFinal Purchase Price Allocation
Purchase price$708.2 $— $708.2 
Inventories, net102.8 0.7 103.5 
Other current assets0.4 (0.1)0.4 
Property, plant and equipment609.3 1.0 610.3 
Other assets, net11.8 — 11.8 
Total assets acquired724.3 1.6 725.9 
Current portion of long-term debt(0.6)— (0.6)
Accounts payable and accrued liabilities(7.7)(0.8)(8.5)
Long-term debt(8.9)— (8.9)
Other long-term obligations(12.6)— (12.6)
Total liabilities assumed(29.7)(0.8)(30.5)
Net assets acquired694.5 0.8 695.3 
Goodwill13.7 (0.8)12.9 
Total estimated fair value of net assets acquired$708.2 $— $708.2 
Business Combination, Pro Forma Information
Nine Months Ended September 30,
2024
Net sales$1,185.3 
Net income (loss)(16.1)
v3.25.3
Discontinued Operations and Disposal Groups (Tables)
 9 Months Ended
Sep. 30, 2025
Discontinued Operations and Disposal Groups [Abstract]  
Disposal Groups, Including Discontinued Operations
 Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Net sales$— $262.4 $— $768.3 
Cost of sales0.1 212.2 1.0 611.1 
Selling, general and administrative expenses0.1 7.0 0.3 22.7 
Depreciation and amortization— 6.7 — 35.0 
Gain on business divestiture(1.1)— (1.1)— 
Other operating charges, net0.1 6.3 1.6 10.8 
Income (loss) from discontinued operations0.8 30.1 (1.8)88.7 
Other non-operating expense— (8.0)— (19.7)
   Total non-operating expense— (8.0)— (19.7)
Income (loss) from discontinued operations before income taxes0.8 22.1 (1.8)68.9 
Income tax provision (benefit)0.2 5.6 (1.2)17.4 
Income (loss) from discontinued operations, net of tax$0.6 $16.6 $(0.7)$51.6 
The major components of “Other operating charges, net” included in discontinued operations for the quarter and nine months ended September 30, 2025 and 2024 are reflected in the table below.
Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Divestiture related costs$0.1 $6.2 $1.6 $10.5 
Loss on sale or impairment associated with assets— 0.1 — 0.3 
$0.1 $6.3 $1.6 $10.8 
During the quarter ended September 30, 2025, we finalized the working capital adjustment associated with the business divestiture, resulting in a $1.1 million gain due to the reversal of a portion of the previously accrued settlement amount. The final cash payment totaled $12.1 million.
Operating and investing cash flows of the discontinued operation are presented in the following table:
 Nine Months Ended September 30,
20252024
Net cash provided by (used in) operating activities of discontinued operations$(1.4)$133.8 
Net cash used in investing activities of discontinued operations— (9.8)
v3.25.3
Fair Value Measures and Disclosures (Tables)
 9 Months Ended
Sep. 30, 2025
Fair Value Disclosures [Abstract]  
Fair Value Option, Disclosures
September 30, 2025December 31, 2024
2020 Notes, maturing 2028, fixed interest rate$257.8 $258.9 
ABL Credit Agreement, variable interest rate54.0 — 
$311.8 $258.9 
v3.25.3
Receivables, net (Tables)
 9 Months Ended
Sep. 30, 2025
Receivables, Net, Current [Abstract]  
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]
September 30, 2025December 31, 2024
Trade accounts receivable$144.3 $167.5 
Allowance for current expected credit losses(1.8)(1.6)
Unbilled receivables5.4 5.3 
Taxes receivable8.4 2.6 
Other5.3 15.0 
$161.7 $188.7 
v3.25.3
Inventories - (Tables)
 9 Months Ended
Sep. 30, 2025
Inventory Disclosure [Abstract]  
Inventories
September 30, 2025December 31, 2024
Logs, chips and sawdust$27.5 $25.1 
Pulp8.4 6.9 
Paperboard products136.9 123.4 
Materials and supplies110.4 102.5 
$283.2 $258.0 
v3.25.3
Property, Plant, and Equipment (Tables)
 9 Months Ended
Sep. 30, 2025
Property, Plant and Equipment [Abstract]  
Property, Plant and Equipment
September 30, 2025December 31, 2024
Land and land improvements$65.7 $65.8 
Buildings and improvements232.6 232.4 
Machinery and equipment2,028.9 1,942.6 
Construction in progress52.3 87.6 
2,379.5 2,328.4 
Less accumulated depreciation and amortization(1,363.6)(1,305.4)
Property, plant and equipment, net$1,015.9 $1,023.1 
v3.25.3
Intangible Assets, Goodwill and Other (Tables)
 9 Months Ended
Sep. 30, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule of Intangible Assets and Goodwill
GoodwillIntangiblesTotal
Balance as of December 31, 2024
$48.6 $4.3 $52.9 
Recognized goodwill - measurement period adjustment(0.7)— (0.7)
Goodwill impairment(48.0)— (48.0)
  Amortization— (1.6)(1.6)
Balance as of September 30, 2025
$— $2.7 $2.7 
v3.25.3
Payables and Accruals (Tables)
 9 Months Ended
Sep. 30, 2025
Payables and Accruals [Abstract]  
Schedule of Accounts Payable and Accrued Liabilities
Accounts payable and accrued liabilities consist of:
September 30, 2025December 31, 2024
Trade payables$145.7 $164.6 
Accrued compensation31.6 38.2 
Operating lease liabilities11.8 11.1 
Taxes payable— 50.8 
Accrued discounts12.1 8.9 
Other30.5 46.1 
$231.7 $319.7 
v3.25.3
Debt (Tables)
 9 Months Ended
Sep. 30, 2025
Debt Disclosure [Abstract]  
Schedule of Long-Term Debt Instruments
September 30, 2025December 31, 2024
Interest Rate at September 30, 2025PrincipalUnamortized Debt CostsTotalPrincipalUnamortized Debt CostsTotal
2020 Notes, maturing 2028, fixed interest rate4.75%$275.0 $(1.5)$273.5 $275.0 $(1.8)$273.2 
ABL Credit Agreement (revolving loan), maturing 2027, variable interest rate5.49%54.0 — 54.0 — — — 
Finance leases8.6 — 8.6 9.1 — 9.1 
Total debt337.6 (1.5)336.1 284.1 (1.8)282.2 
Less: current portion(0.6)— (0.6)(0.6)— (0.6)
Net long-term portion$337.0 $(1.5)$335.5 $283.4 $(1.8)$281.6 
v3.25.3
Other Operating Charges, net (Tables)
 9 Months Ended
Sep. 30, 2025
Other Income and Expenses [Abstract]  
Schedule of Other Operating Cost and Expense, by Component [Table Text Block]
Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Acquisition related costs$— $0.5 $— $13.9 
Integration costs0.5 2.3 5.2 5.7 
Cost reduction plan— — 6.1 — 
Loss on sale or impairment associated with assets1.9 0.4 5.1 1.1 
Directors' equity-based compensation expense(1.0)(3.5)(0.5)(0.4)
Other— — 4.5 — 
$1.5 $(0.3)$20.4 $20.3 
v3.25.3
Non-operating Income (Expense) (Tables)
 9 Months Ended
Sep. 30, 2025
Nonoperating Income (Expense) [Abstract]  
Schedule of Other Nonoperating Income (Expense) [Table Text Block]
Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Interest expense$(4.5)$(13.0)$(11.8)$(24.6)
Amortization of debt issuance costs(0.6)(0.6)(1.7)(1.2)
Interest income0.3 0.4 1.4 1.8 
Interest expense, net(4.7)(13.1)(12.0)(24.0)
Non-operating pension and other postretirement employee benefits(0.3)0.3 (0.9)1.0 
Total non-operating expense$(5.0)$(12.8)$(12.9)$(22.9)
v3.25.3
Retirement Plans and Postretirement Benefits - (Tables)
 9 Months Ended
Sep. 30, 2025
Retirement Benefits [Abstract]  
Components of Net Periodic Cost of Pension and Other Postretirement Employee Benefit Plans
 Quarter Ended September 30,Nine Months Ended September 30,
Pension Benefit Plans2025202420252024
Service cost$0.8 $0.6 $2.3 $1.9 
Interest cost3.0 3.0 8.9 8.9 
Expected return on plan assets(3.3)(3.9)(10.0)(11.8)
Amortization of actuarial loss0.2 — 0.6 0.1 
Net periodic cost $0.6 $(0.3)$1.7 $(0.9)

 Quarter Ended September 30,Nine Months Ended September 30,
Other Postretirement Employee Benefit Plans2025202420252024
Service cost$— $0.1 $0.1 $0.2 
Interest cost0.6 0.7 1.9 2.0 
Amortization of actuarial gain(0.1)(0.1)(0.4)(0.2)
Net periodic cost$0.5 $0.6 $1.6 $2.0 
v3.25.3
Accumulated Other Comprehensive Loss (Tables)
 9 Months Ended
Sep. 30, 2025
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]  
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]
Pension Plan AdjustmentsOther Post Retirement Employee Benefit Plan AdjustmentsTotal
Balance at December 31, 2023$(42.0)$11.3 $(30.7)
Amounts reclassified from accumulated other comprehensive loss0.1 (0.2)(0.1)
Balance at September 30, 2024$(41.9)$11.1 $(30.8)
Balance at December 31, 2024$(47.8)$13.4 $(34.5)
Amounts reclassified from accumulated other comprehensive loss0.4 (0.3)0.1 
Balance at September 30, 2025$(47.4)$13.1 $(34.3)
v3.25.3
Stockholders' Equity - (Tables)
 9 Months Ended
Sep. 30, 2025
Share-Based Payment Arrangement [Abstract]  
Employee Equity-Based Compensation Expense
Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Total stock-based compensation expense (income)$0.6 $(0.9)$4.1 $7.2 
Income tax provision (benefit) related to stock-based compensation$— $(0.5)$0.2 $0.8 
Impact on cash flow from proceeds on options exercised$— $0.2 $— $1.3 
Impact on cash flow due to taxes paid related to net share settlement of equity awards$— $0.1 $2.3 $4.1 
v3.25.3
Restructuring and Related Activities (Tables)
 9 Months Ended
Sep. 30, 2025
Restructuring and Related Activities [Abstract]  
Restructuring and Related Costs
 Total
Balance at December 31, 2024$— 
Employee severance charges included in "other operating charges, net"5.0 
Cost paid or otherwise settled(4.6)
Balance at September 30, 2025$0.4 
v3.25.3
Segment Reporting (Tables)
 9 Months Ended
Sep. 30, 2025
Segment Reporting [Abstract]  
Reconciliation of Operating Profit (Loss) from Segments to Consolidated
Quarter Ended September 30,Nine Months Ended September 30,
2025202420252024
Net sales by product line:
Food service$182.0 $142.1 $499.3 $366.5 
Folding carton143.0 182.1 438.9 436.7 
Sheeting and distribution37.9 41.6 116.5 123.2 
Pulp and other36.1 27.5 114.4 70.2 
Total net sales$399.0 $393.3 $1,169.0 $996.5 
Input cost (raw materials and energy)173.5 177.2 518.5 438.6 
Labor and overhead142.1 129.4 387.2 344.5 
Supply chain costs (principally freight)40.6 39.5 116.0 101.4 
Selling, general and administrative expenses23.7 30.7 76.6 86.9 
Goodwill impairment charge48.0 — 48.0 — 
Depreciation and amortization23.8 22.4 68.7 48.4 
Interest expense, net4.7 13.1 12.0 24.0 
Non-significant expenses3.0 (5.0)4.6 24.5 
Income tax benefit(6.5)(3.3)(6.3)(17.4)
Loss from continuing operations$(53.9)$(10.7)$(56.2)$(54.4)
v3.25.3
Business Combinations and Asset Acquisitions (Details) - USD ($)
$ in Millions
 9 Months Ended
May 01, 2024
Sep. 30, 2025
Sep. 30, 2024
Dec. 31, 2024
Business Combination [Line Items]        
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory   $ 0.7    
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment   1.0    
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Assets   1.6    
BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAccountsPayable   (0.8)    
Goodwill, Measurement Period Adjustment   (0.7)    
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net   0.0   $ 48.6
Business Combination, Pro Forma Information, Pro Forma Revenue     $ 1,185.3  
Business Combination, Pro Forma Information, Pro Forma Income (Loss), after Tax     $ (16.1)  
Augusta, Georgia Mill Acquisition [Member]        
Business Combination [Line Items]        
Business Combination, Consideration Transferred $ 708.2 708.2    
Business Combination, Recognized Asset Acquired, Inventory, Current 102.8 103.5    
Business Combination, Recognized Asset Acquired, Other Asset, Current 0.4 0.4    
BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherCurrentAsset   0.1    
Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment 609.3 610.3    
Business Combination, Recognized Asset Acquired, Other Asset, Noncurrent 11.8 11.8    
Business Combination, Recognized Asset Acquired, Asset 724.3 725.9    
Business Combination, Recognized Liability Assumed, Long-Term Debt, Current (0.6) (0.6)    
Business Combination, Recognized Liability Assumed, Other Liability, Current (7.7) (8.5)    
Business Combination, Recognized Liability Assumed, Long-Term Debt, Noncurrent (8.9) (8.9)    
Business Combination, Recognized Liability Assumed, Other Liability, Noncurrent (12.6) (12.6)    
Business Combination, Recognized Liability Assumed, Liability (29.7) (30.5)    
BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentTotalLiabilitiesAssumed   0.8    
Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less) 694.5 695.3    
BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentNetAssetsAcquired   0.8    
Goodwill, Measurement Period Adjustment   (0.8)    
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net 13.7 12.9    
Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill $ 708.2 $ 708.2    
v3.25.3
Discontinued Operations and Disposal Groups (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]        
Disposal Group, Including Discontinued Operation, Revenue $ 0.0 $ 262.4 $ 0.0 $ 768.3
Disposal Group, Including Discontinued Operation, Costs of Goods Sold 0.1 212.2 1.0 611.1
Disposal Group, Including Discontinued Operation, General and Administrative Expense 0.1 7.0 0.3 22.7
Disposal Group, Including Discontinued Operation, Depreciation and Amortization 0.0 6.7 0.0 35.0
Gain (Loss) on Disposition of Business (1.1) 0.0 (1.1) 0.0
Disposal Group, Including Discontinued Operation, Operating Income (Loss) 0.8 30.1 (1.8) 88.7
Disposal Group, Including Discontinued Operation, Other Expense 0.1 6.3 1.6 10.8
Gain (Loss) on Sale of Assets and Asset Impairment Charges 0.0 0.1 0.0 0.3
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax 0.8 22.1 (1.8) 68.9
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation 0.2 5.6 (1.2) 17.4
Income (Loss) from discontinued operations, net of tax 0.6 16.6 (0.7) 51.6
Cash Provided by (Used in) Operating Activity, Discontinued Operation     (1.4) 133.8
Cash Provided by (Used in) Investing Activity, Discontinued Operation     0.0 (9.8)
Proceeds from (Payment for) Other Financing Activity     (2.8) (2.7)
Proceeds from Divestiture of Businesses     12.1 0.0
Other Nonoperating Income (Expense)        
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]        
Disposal Group, Including Discontinued Operation, Other Expense 0.0 8.0 0.0 19.7
Other Expense [Member]        
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]        
Disposal Group, Including Discontinued Operation, Other Expense $ 0.1 $ 6.2 $ 1.6 $ 10.5
v3.25.3
Fair Value Measures and Disclosures (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Dec. 31, 2024
Fair Value, Option, Quantitative Disclosures [Line Items]    
Long-term Debt, Fair Value $ 311.8 $ 258.9
Senior Notes    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Long-term Debt, Fair Value 257.8 258.9
JPMorgan Chase Bank    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Long-term Debt, Fair Value $ 54.0 $ 0.0
v3.25.3
Receivables, net (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Dec. 31, 2024
Receivables, Net, Current [Abstract]    
Trade accounts receivable $ 144.3 $ 167.5
Accounts Receivable, Allowance for Credit Loss, Current (1.8) (1.6)
Unbilled Receivables, Current 5.4 5.3
Income Taxes Receivable, Current 8.4 2.6
Other Receivables, Net, Current 5.3 15.0
Receivables, Net $ 161.7 $ 188.7
v3.25.3
Inventories - Inventories (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Dec. 31, 2024
Inventory Disclosure [Abstract]    
Inventories $ 283.2 $ 258.0
Inventory [Line Items]    
Inventory, Finished Goods, Net of Reserves 136.9 123.4
Inventory, Supplies, Net of Reserves 110.4 102.5
Inventories 283.2 258.0
Inventories    
Inventory [Line Items]    
Inventory, Raw Materials, Net of Reserves 27.5 25.1
Inventory Pulp    
Inventory [Line Items]    
Inventory, Raw Materials, Net of Reserves $ 8.4 $ 6.9
v3.25.3
Property, Plant, and Equipment (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Dec. 31, 2024
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Gross $ 2,379.5 $ 2,328.4
Accumulated Depreciation and Amortization, Property, Plant, and Equipment (1,363.6) (1,305.4)
Property, Plant and Equipment, Net 1,015.9 1,023.1
Land and Land Improvements    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Gross 65.7 65.8
Building and Building Improvements    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Gross 232.6 232.4
Machinery and Equipment    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Gross 2,028.9 1,942.6
Construction in Progress    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Gross $ 52.3 $ 87.6
v3.25.3
Intangible Assets, Goodwill and Other (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Dec. 31, 2024
May 01, 2024
Goodwill [Line Items]            
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net $ 0.0   $ 0.0   $ 48.6  
Intangible Assets, Net (Excluding Goodwill) 2.7   2.7   4.3  
Goodwill and intangible assets 2.7   2.7   $ 52.9  
Goodwill, Measurement Period Adjustment     (0.7)      
Goodwill, Impairment Loss 48.0 $ 0.0 48.0 $ 0.0    
Amortization of Intangible Assets     (1.6)      
Manchester Industries, Mill Acquisition            
Goodwill [Line Items]            
Goodwill, Impairment Loss     35.1      
Augusta, Georgia Mill Acquisition [Member]            
Goodwill [Line Items]            
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net $ 12.9   12.9     $ 13.7
Goodwill, Measurement Period Adjustment     (0.8)      
Goodwill, Impairment Loss     $ 12.9      
v3.25.3
Payables and Accruals (Details) - USD ($)
$ in Millions
 9 Months Ended 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
 [1]
Dec. 31, 2024
Payables and Accruals [Abstract]      
Trade payables $ 145.7   $ 164.6
Accrued compensation 31.6   38.2
Operating Lease, Liability, Current 11.8   11.1
Taxes Payable, Current 0.0   50.8
Accounts Payable and Other Accrued Liabilities 12.1   8.9
Other Accrued Liabilities, Current 30.5   46.1
Accounts payable and accrued liabilities 231.7   319.7
Capital Expenditures Incurred but Not yet Paid 11.8 [1] $ 25.5 25.8
Supplier Finance Program, Obligation $ 6.3   $ 12.7
[1] Capital expenditures of $11.8 million and $25.5 million that have not been paid as of September 30, 2025 and 2024 were excluded from the Statements of Cash Flows.
v3.25.3
Income Taxes - Narrative (Detail) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Income Tax Disclosure [Abstract]        
Income Tax Expense (Benefit) $ (6.5) $ (3.3) $ (6.3) $ (17.4)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent     21.00%  
v3.25.3
Debt (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Dec. 31, 2024
Debt Instrument [Line Items]    
Long-Term Debt, Gross $ 337.6 $ 284.1
Long-Term Debt and Lease Obligation, Current (0.6) (0.6)
Long-term debt, net 335.5 281.6
Long-Term Debt and Lease Obligation 337.0 283.4
Unamortized Debt Issuance Expense (1.5) (1.8)
Long-Term Debt 273.5 273.2
Finance Lease, Liability 8.6 9.1
Long-Term Debt and Lease Obligation, Including Current Maturities 336.1 282.2
Line of Credit Facility, Maximum Borrowing Capacity 264.6  
Long-Term Line of Credit 57.7  
Letters of Credit Outstanding, Amount 3.7  
Line of Credit Facility, Remaining Borrowing Capacity $ 213.9  
AnnualTermRevolverReductionPercentage 2.00%  
TermRevolverSpringingMaturityAdditionalAmountThreshold $ 50.0  
JPMorgan Chase Bank    
Debt Instrument [Line Items]    
Line of Credit Facility, Maximum Borrowing Capacity 375.0  
Potential additional lines of credit 100.0  
AgWest Farm Credit    
Debt Instrument [Line Items]    
Potential additional lines of credit $ 60.0  
Senior Notes    
Debt Instrument [Line Items]    
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate 4.75%  
Long-Term Debt, Gross $ 275.0 275.0
Unamortized Debt Issuance Expense $ (1.5) (1.8)
JPMorgan Chase Bank    
Debt Instrument [Line Items]    
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate 5.49%  
Long-Term Debt, Gross   0.0
Long-Term Debt $ 54.0 $ 0.0
Loans | AgWest Farm Credit    
Debt Instrument [Line Items]    
Long-Term Debt, Gross $ 0.0  
v3.25.3
Other Operating Charges, net (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Other Operating Income (Expense), Net $ 1.5 $ (0.3) $ 20.4 $ 20.3
Severance Costs (0.1)   5.0  
Operating Expense        
Asset Impairment Charges 1.9 0.4 5.1 1.1
Other Operating expenses, net 0.0 0.0 4.5 0.0
Business Combination, Integration-Related Cost, Expense 0.5 2.3 5.2 5.7
Business Combination, Acquisition-Related Cost, Expense 0.0 0.5 0.0 13.9
Continuing Operations        
Severance Costs 0.0 0.0 6.1 0.0
Director [Member]        
Share based compensation expense $ (1.0) $ (3.5) $ (0.5) $ (0.4)
v3.25.3
Non-operating Income (Expense) (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Nonoperating Income (Expense) [Abstract]        
Interest Expense $ (4.5) $ (13.0) $ (11.8) $ (24.6)
Amortization of Debt Issuance Costs (0.6) (0.6) (1.7) (1.2)
Interest Income, Other 0.3 0.4 1.4 1.8
Interest Expense, Net (4.7) (13.1) (12.0) (24.0)
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component (0.3) 0.3 (0.9) 1.0
Total non-operating expense $ (5.0) $ (12.8) $ (12.9) $ (22.9)
v3.25.3
Retirement Plans and Postretirement Benefits - Narrative (Detail) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Pension Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Service Cost $ 0.8 $ 0.6 $ 2.3 $ 1.9
Interest cost 3.0 3.0 8.9 8.9
Expected return on plan assets (3.3) (3.9) (10.0) (11.8)
Defined Benefit Plan, Amortization of Gain (Loss) 0.2 0.0 0.6 0.1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) 0.6 (0.3) 1.7 (0.9)
Other Postretirement Benefits Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Service Cost 0.0 0.1 0.1 0.2
Interest cost 0.6 0.7 1.9 2.0
Defined Benefit Plan, Amortization of Gain (Loss) (0.1) (0.1) (0.4) (0.2)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) 0.5 0.6 1.6 2.0
Cost of Sales [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax 0.6 0.6 2.0 1.7
Selling, General and Administrative Expenses [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax $ 0.2 0.1 $ 0.4 0.4
Discontinued Operations        
Defined Benefit Plan Disclosure [Line Items]        
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax   $ 0.1   $ 0.2
v3.25.3
Accumulated Other Comprehensive Loss (Details) - USD ($)
$ in Millions
 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Dec. 31, 2024
Dec. 31, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]        
Accumulated Other Comprehensive Income (Loss), Net of Tax $ (34.3) $ (30.8) $ (34.5) $ (30.7)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]        
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax 0.1 (0.1)    
Pension Plan [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]        
Accumulated Other Comprehensive Income (Loss), Net of Tax (47.4) (41.9) (47.8) (42.0)
Pension Plan [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]        
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax 0.4 0.1    
Other Postretirement Benefits Plan [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]        
Accumulated Other Comprehensive Income (Loss), Net of Tax 13.1 11.1 $ 13.4 $ 11.3
Other Postretirement Benefits Plan [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]        
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]        
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax $ (0.3) $ (0.2)    
v3.25.3
Stockholders' Equity - (Detail) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 600,000   600,000  
Equity-based compensation expense $ 0.6 $ (0.9) $ 4.1 $ 7.2
Payment, Tax Withholding, Share-based Payment Arrangement 0.0 0.1 2.3 4.1
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount 10.8   10.8  
Share-based Payment Arrangement, Expense, Tax Benefit 0.0 (0.5) 0.2 0.8
Proceeds from Stock Options Exercised 0.0 0.2 0.0 1.3
Cost of Sales [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax $ 0.6 0.6 $ 2.0 1.7
Continuing Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Equity-based compensation expense   1.3   6.0
Discontinued Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Equity-based compensation expense   $ 0.4   $ 1.2
Restricted Stock Units (RSUs) [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of share-based awards granted     198,887  
Grant-date fair value of awards per share     $ 28.36  
Performance Shares [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of share-based awards granted     194,378  
Grant-date fair value of awards per share     $ 31.04  
v3.25.3
Earnings per Common Share - Reconciliation of Number of Common Shares Used in Calculating Basic and Diluted Net Earnings Per Share (Detail) - shares
shares in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Anti-dilutive shares excluded from calculation 0.3 0.3 0.3 0.4
v3.25.3
Restructuring and Related Activities (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2025
Dec. 31, 2024
Restructuring and Related Activities [Abstract]      
Restructuring Reserve, Current $ 0.4 $ 0.4 $ 0.0
Severance Costs (0.1) 5.0  
Payments for Restructuring   (4.6)  
Minimum      
Restructuring Cost and Reserve [Line Items]      
Restructuring and Related Cost, Expected Cost 5.0 5.0  
Maximum      
Restructuring Cost and Reserve [Line Items]      
Restructuring and Related Cost, Expected Cost $ 7.0 $ 7.0  
v3.25.3
Segment Reporting (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]        
Net Sales $ 399.0 $ 393.3 $ 1,169.0 $ 996.5
Cost of sales 380.3 363.2 1,070.6 935.1
Other Selling, General and Administrative Expense 23.7 30.7 76.6 86.9
Goodwill, Impairment Loss 48.0 0.0 48.0 0.0
Other Depreciation and Amortization 23.8 22.4 68.7 48.4
Interest Expense, Net 4.7 13.1 12.0 24.0
Segment Reporting, Other Segment Item, Amount 3.0 (5.0) 4.6 24.5
Income Tax Expense (Benefit) (6.5) (3.3) (6.3) (17.4)
Income (Loss) from Continuing Operations, Net of Tax (53.9) (10.7) (56.2) (54.4)
Cost of Sales [Member]        
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]        
Cost of sales 173.5 177.2 518.5 438.6
Labor and Overhead        
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]        
Cost of sales 142.1 129.4 387.2 344.5
Supply Chain Costs        
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]        
Cost of sales 40.6 39.5 116.0 101.4
Foodservice        
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]        
Net Sales 182.0 142.1 499.3 366.5
Folding Carton        
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]        
Net Sales 143.0 182.1 438.9 436.7
Sheeting and Distribution        
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]        
Net Sales 37.9 41.6 116.5 123.2
Other        
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]        
Net Sales $ 36.1 $ 27.5 $ 114.4 $ 70.2
v3.25.3
Unusual or Infrequently Occurring Items (Details)
$ in Millions
 6 Months Ended
Jun. 30, 2024
USD ($)
Unusual or Infrequent Item, or Both [Line Items]  
Unusual or Infrequent Item, or Both, Insurance Proceeds $ 10.5
Discontinued Operations  
Unusual or Infrequent Item, or Both [Line Items]  
Unusual or Infrequent Item, or Both, Insurance Proceeds 0.9
Continuing Operations  
Unusual or Infrequent Item, or Both [Line Items]  
Unusual or Infrequent Item, or Both, Insurance Proceeds 9.3
Insurance Claims  
Unusual or Infrequent Item, or Both [Line Items]  
Insurance Recoveries 5.8
Property, Plant and Equipment  
Unusual or Infrequent Item, or Both [Line Items]  
Unusual or Infrequent Item, or Both, Insurance Proceeds 0.3
Insurance Settlement  
Unusual or Infrequent Item, or Both [Line Items]  
Insurance Recoveries $ 4.7