Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Litigation Brazil SWM-Brazil ("SWM-B") received assessments from the tax authorities of the State of Rio de Janeiro (the "State") for unpaid Imposto sobre Circulação de Mercadorias e Serviços ("ICMS") and Fundo Estadual de Combate à Pobreza ("FECP") value-added taxes on interstate purchases of electricity. The State issued four sets of assessments against SWM-B for periods from May 2006 through December 2017 (collectively the "Electricity Assessments"). The first through fourth assessments were received in February 2008, June 2011, October 2013, and August 2018, respectively. SWM-B challenged all Electricity Assessments in administrative proceedings before the State tax council (in the Junta de Revisão Fiscal “first-level administrative court” and the Conselho de Contribuintes “administrative appellate court”) based on Resolution 1.610/89, which defers these taxes on electricity purchased by an "electricity-intensive consumer." In 2014, a majority of the administrative appellate court sitting en banc ruled against SWM-B in each of the first and second Electricity Assessments ($12.3 million based on the foreign currency exchange rate at June 30, 2023), and SWM-B is now pursuing challenges to these assessments in the State judicial system where SWM-B obtained preliminary injunctions against enforcement of both assessments. In March 2020, the first-level judicial court ruled in favor of SWM-B in the second Electricity Assessment, a decision that is now on appeal. The third Electricity Assessment was dismissed on technical grounds in 2018. In August 2018, the State filed revised fourth Electricity Assessments for a combined amount of $10.3 million. SWM-B filed challenges to these 2018 assessments in the first-level administrative court on the same grounds as the older cases, receiving unfavorable rulings from the courts in 2019. Both 2019 decisions are being appealed. The State issued a new regulation effective January 1, 2018 that only specific industries are “electricity-intensive consumers,” a list that excludes paper manufacturers. SWM-B contends this regulation shows that paper manufacturers were electricity-intensive consumers eligible to defer ICMS before 2018. As SWM-B cannot determine the outcome of the Electricity Assessments matters, no loss has been accrued in our unaudited condensed consolidated financial statements. Germany In January 2015, the Company initiated patent infringement proceedings in Germany against Glatz under multiple low ignition propensity ("LIP") related patents. In December 2017, the Dusseldorf Appeal Court affirmed the German District Court judgment on infringement of EP1482815 against Glatz. The Company filed an action against Glatz in the German District Court to set the amount of damages for the infringement and Glatz filed a counterclaim. Glatz filed an action in the German Patent Court to invalidate the German part of EP1482815. The German Patent Court held that some of the patent claims at issue were invalid and also that another claim at issue was valid. The Company appealed the portion of the decision with respect to the claims held to be invalid. The German Supreme Court held that the claims of German counterpart of EP1482815 relevant to the Glatz infringement action were invalid. This ruling has the effect of nullifying the infringement decision and injunction against Glatz and the Company’s claim for damages against Glatz. Glatz’s counterclaim against the Company was settled in June 2023. The Company recognized a $4.9 million loss during the three months ended June 30, 2023, which is included in Other income (expense), net in the unaudited Condensed Consolidated Statements of Income (Loss). Environmental Matters The Company's operations are subject to various nations' federal, state and local laws, regulations and ordinances relating to environmental matters. The nature of the Company's operations exposes it to the risk of claims with respect to various environmental matters, and there can be no assurance that material costs or liabilities will not be incurred in connection with such claims. While the Company has incurred in the past several years, and will continue to incur, capital and operating expenditures in order to comply with environmental laws and regulations, it believes that its future cost of compliance with environmental laws, regulations and ordinances, and its exposure to liability for environmental claims and its obligation to participate in the remediation and monitoring of certain hazardous waste disposal sites, will not have a material effect on its financial condition or results of operations. However, future events, such as changes in existing laws and regulations, or unknown contamination or costs of remediation of sites owned, operated or used for waste disposal by the Company (including contamination caused by prior owners and operators of such sites or other waste generators) may give rise to additional costs which could have a material effect on its financial condition or results of operations. Employees and Labor Relations As of June 30, 2023, approximately 21% of the Company's U.S. workforce and 37% of its Non-U.S. workforce are under collective bargaining agreements. Approximately 1% of all U.S. employees and 30% of Non-U.S. employees are under collective bargaining agreements that will expire in the next 12 months. For the Non-U.S. workforce, union membership is voluntary and does not need to be disclosed to the Company under local laws. As a result, the number of employees covered by the collective bargaining agreements in some countries cannot be determined. General Matters In the ordinary course of conducting business activities, the Company and its subsidiaries become involved in certain other judicial, administrative and regulatory proceedings involving both private parties and governmental authorities. These proceedings include insured and uninsured regulatory, employment, intellectual property, general and commercial liability, environmental and other matters. At this time, the Company does not expect any of these proceedings to have a material effect on its reputation, business, financial condition, results of operations or cash flows. However, the Company can give no assurance that the results of any such proceedings will not materially affect its reputation, business, financial condition, results of operations or cash flows.