| Cover - USD ($) $ in Millions | 12 Months Ended | | |
| Dec. 31, 2024 | Feb. 21, 2025 | Jun. 30, 2024 |
| Cover [Abstract] | | | |
| Current Fiscal Year End Date | --12-31 | | |
| Entity Well-known Seasoned Issuer | No | | |
| Document Type | 10-K/A | | |
| Document Annual Report | true | | |
| Document Transition Report | false | | |
| Entity File Number | 001-34146 | | |
| Registrant Name | CLEARWATER PAPER CORPORATION | | |
| Entity Incorporation, State or Country Code | DE | | |
| Entity Tax Identification Number | 20-3594554 | | |
| Entity Address, Postal Zip Code | 99201 | | |
| Entity Address, Address Line Two | Suite 1100 | | |
| Entity Address, Address Line One | 601 West Riverside, | | |
| Entity Address, State or Province | WA | | |
| Entity Address, City or Town | Spokane, | | |
| City Area Code | 509 | | |
| Local Phone Number | 344-5900 | | |
| Title of 12(b) Security | Common Stock ($0.0001 par value per share) | | |
| Trading Symbol | CLW | | |
| Security Exchange Name | NYSE | | |
| Entity Filer Category | Large Accelerated Filer | | |
| Entity Small Business | false | | |
| Entity Emerging Growth Company | false | | |
| ICFR Auditor Attestation Flag | true | | |
| Document Financial Statement Error Correction [Flag] | false | | |
| Entity Shell Company | false | | |
| Entity Public Float | | | $ 788.5 |
| Entity Common Stock, Shares Outstanding | | 16,175,161 | |
| Amendment Description | Clearwater Paper Corporation (the “Company”) is filing this Amendment No. 1 on Form 10-K/A (this “Amendment”) to amend the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024 (the “Original Filing”), which was originally filed with the U.S. Securities and Exchange Commission (the “SEC”) on February 24, 2025 (the “Original Filing Date”). The sole purpose of this Amendment is to amend the Exhibits contained in Item 15 of Part IV of the Original Filing to include Exhibit 19.1, Clearwater Paper Corporation Insider Trading Policy, which was inadvertently omitted in the Original Filing.This Amendment is an exhibit-only filing. Except as described above, no changes have been made to the Original Filing and this Amendment does not modify, amend, or update in any way any of the financial or other information contained in the Original Filing. This Amendment does not reflect events that may have occurred subsequent to the Original Filing Date. Accordingly, this Amendment should be read in conjunction with the Original Filing and the Company’s other filings with the SEC.Pursuant to Rule 12b-15 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), currently dated certifications are filed herewith as exhibits to this Amendment pursuant to Rule 13a-14(a) or 15d-14(a) of the Exchange Act. These certifications are attached to this Amendment as Exhibit 31.1 under Item 15 of Part IV hereof. Because no financial statements are being filed with this Amendment and this Amendment does not contain any disclosure with respect to Items 307 and 308 of Regulation S-K, paragraphs 3, 4, and 5 of the certifications have been omitted. Similarly, because no financial statements are being filed with this Amendment, certifications pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 have been omitted. | | |
| Entity Voluntary Filers | No | | |
| Entity Current Reporting Status | Yes | | |
| Entity Interactive Data Current | Yes | | |
| Document Fiscal Year Focus | 2024 | | |
| Central Index Key | 0001441236 | | |
| Amendment Flag | true | | |
| Document Period End Date | Dec. 31, 2024 | | |
| Document Information [Line Items] | | | |
| Document Fiscal Period Focus | FY | | |
| Document Fiscal Year Focus | 2024 | | |
| Document Period End Date | Dec. 31, 2024 | | |
| Current Fiscal Year End Date | --12-31 | | |
