Percentage of entity's employees covered by collective-bargaining arrangement (CBA) to all entity's employees in multiemployer pension plan determined to be individually significant.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 5
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947

Name:	us-gaap_MultiemployerPlanPensionSignificantEmployeesCoveredByCollectiveBargainingArrangementToAllEntitysEmployeesPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Employee Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
Employee Benefit Plans (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
UMWA Collective Bargaining Agreement
Defined Contribution Plan Disclosure [Line Items]
Proportion of company's employees represented by CBA (as a percent)		67.20%
Successor Benefit Plan
Defined Contribution Plan Disclosure [Line Items]
Contributions to defined contribution plans	$ 2.5	$ 3.0	$ 2.9