Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Components of deferred tax assets and liabilities. [Line Items]
Deferred tax assets, net of valuation allowance	$ 181.6	$ 181.6
Deferred tax liabilities	9.8	9.8
Valuation allowance	19.2	19.2
Reserves for uncertain tax positions	196.9	196.9	$ 175.9
Unrecognized tax benefits	0.1	0.1	$ 0.3
Deferred tax expenses related to contract fair value amortization	4.7	8.9
Foreign Tax Authority | Guyana, Norway, Switzerland And Luxembourg
Components of deferred tax assets and liabilities. [Line Items]
Deferred foreign tax benefits	50.7
Foreign Tax Authority | GUYANA
Components of deferred tax assets and liabilities. [Line Items]
Deferred foreign tax benefits		84.6
Foreign Tax Authority | NORWAY
Components of deferred tax assets and liabilities. [Line Items]
Deferred foreign tax benefits		3.9
Foreign Tax Authority | SWITZERLAND
Components of deferred tax assets and liabilities. [Line Items]
Deferred foreign tax benefits		7.2
Foreign Tax Authority | GHANA
Components of deferred tax assets and liabilities. [Line Items]
Tax expense (benefit) related to uncertain tax position	(6.8)	(6.8)
Foreign Tax Authority | Mexico
Components of deferred tax assets and liabilities. [Line Items]
Tax expense (benefit) related to uncertain tax position	9.8	9.8
Foreign Tax Authority | Guyana, Australia And Luxembourg
Components of deferred tax assets and liabilities. [Line Items]
Tax expenses (benefits) related to various recurring items	$ 42.2	67.4
Foreign Tax Authority | Guyana, Norway And Switzerland
Components of deferred tax assets and liabilities. [Line Items]
Tax expense (benefit) related to uncertain tax position		$ (95.8)