Financial Instruments and Other Guarantees - Narratives (Details) - USD ($) $ in Millions		3 Months Ended			9 Months Ended
	Feb. 03, 2023	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Apr. 14, 2023	Mar. 31, 2023	Feb. 13, 2023	Dec. 31, 2022
Guarantee Obligations [Line Items]
Line of Credit Facility, Current Borrowing Capacity							$ 237.2
Cumulative Collateral			$ 557.8
Net loss on early debt extinguishment		$ 0.0		$ 8.7	$ 8.8	$ 34.5
Interest expense		13.8		33.8	45.5	110.8
Restricted Cash		643.1			643.1					$ 110.3
Difference between penal sum of all surety bonds and amount of collateral posted in favor of surety providers		586.1			586.1
Letter of Credit
Guarantee Obligations [Line Items]
Proceeds from Issuance of Debt	$ 324.0
Line of Credit Facility, Increase (Decrease), Net	$ (65.0)
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	6.00%
Line of Credit Facility, Commitment Fee Percentage	0.50%
Collateralized Letter of Credit Agreement
Guarantee Obligations [Line Items]
Letters of credit outstanding, amount		167.0			167.0
Line of credit facility, maximum borrowing capacity		$ 250.0			$ 250.0
Cash Collateral, Percentage of the aggregate amount of letters of credit outstanding		103.00%			103.00%
Cash-collateralized Letters of Credit		$ 172.0			$ 172.0
Stated interest rate		0.75%			0.75%
Surety Trust Account
Guarantee Obligations [Line Items]
Restricted Cash		$ 471.1			$ 471.1			$ 566.3		$ 0.0
Accounts Receivable Securitization Program
Guarantee Obligations [Line Items]
Line of Credit Facility, Previous Maximum Borrowing Capacity									$ 175.0
Line of credit facility, maximum borrowing capacity									$ 225.0
Accounts Receivable Securitization Program | Secured debt
Guarantee Obligations [Line Items]
Letters of credit outstanding, amount		107.4			$ 107.4
Basis spread on variable rate					2.10%
Maximum
Guarantee Obligations [Line Items]
Debt Instrument, Collateral Amount							$ 721.8
Maximum | Collateralized Letter of Credit Agreement
Guarantee Obligations [Line Items]
Transaction support agreements, additional collateral demands		5.0			$ 5.0
Surety Bond
Guarantee Obligations [Line Items]
Debt Instrument, Transaction Support Agreements, Additional Collateral Posted								140.5
Debt Instrument, Transaction Support Agreement, Additional Collateral Held								$ 15.0
Surety Agreement Liquidity Covenant, Amount		400.0			400.0
Debt instrument, transaction support agreements, fair value of second liens on mining equipment		$ 200.0			$ 200.0
Surety Bond | Maximum
Guarantee Obligations [Line Items]
Net Leverage Ratio		1.5			1.5
Surety Bond | Minimum
Guarantee Obligations [Line Items]
Net Leverage Ratio		1.0			1.0
Senior Notes | 3.250% Convertible Senior Notes due March 2028 (2028 Convertible Notes)
Guarantee Obligations [Line Items]
Debt Instrument, Funded, Percent		50.00%			50.00%
Stated interest rate		3.25%			3.25%
Secured debt | Accounts Receivable Securitization Program
Guarantee Obligations [Line Items]
Outstanding borrowings		$ 0.0			$ 0.0
Accounts Receivable from Securitization		79.8			79.8
Interest expense		$ 0.9		$ 1.2	$ 2.8	$ 3.4