Financial Instruments, Guarantees With Off-Balance-Sheet Risk and Other Guarantees (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 31, 2022	Nov. 06, 2020	Apr. 03, 2017
Guarantee Obligations [Line Items]
Letters of credit outstanding, amount	$ 452,600,000
Financial Instrument, Surety Bonds Amount	1,463,700,000
Asset retirement obligations	719,800,000	$ 728,200,000	$ 752,300,000
Surety bonds and bank guarantees outstanding to secure reclamation obligations or activities	1,294,700,000	1,451,900,000
Letters of credit outstanding for reclamation	323,000,000
Interest expense	183,400,000	139,800,000	144,000,000.0
Provision for North Goonyella equipment loss	0	0	83,200,000	$ 66,400,000
Surety Bond
Guarantee Obligations [Line Items]
Transaction support agreements, additional collateral to be posted						$ 75,000,000
Debt instrument, transaction support agreements, fair value of second liens on mining equipment						200,000,000
Transaction support agreements, additional collateral to be posted per year through 2024						25,000,000
Transaction support agreements, additional collateral term, free cash flow in any twelve-month period						100,000,000
Transaction support agreements, additional collateral term, sale of assets benchmark (in excess of)						$ 10,000,000
Obligations
Guarantee Obligations [Line Items]
Restricted cash collateral	0	0	0
Accounts Receivable Securitization Program, April 3, 2020
Guarantee Obligations [Line Items]
Exit facility, maximum borrowing capacity							$ 250,000,000
Line of credit facility, remaining borrowing capacity	26,300,000
Accounts Receivable Securitization Program, April 3, 2020 | Scenario, Forecast
Guarantee Obligations [Line Items]
Exit facility, maximum borrowing capacity					$ 175,000,000
Secured Debt | Accounts Receivable Securitization Program, April 3, 2020
Guarantee Obligations [Line Items]
Letters of credit outstanding, amount	143,900,000
Long-term debt	0
Interest expense	$ 2,900,000	$ 2,600,000	3,300,000
Secured Debt | Accounts Receivable Securitization Program, April 3, 2020 | LIBOR
Guarantee Obligations [Line Items]
Basis spread on variable rate	1.50%
Australian Mining
Guarantee Obligations [Line Items]
Provision for North Goonyella equipment loss			$ 300,000