Income Taxes - Textual (Details) $ in Millions, $ in Billions	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 AUD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2020 AUD ($)
Investments, Owned, Federal Income Tax Note [Line Items]
Remeasurement due to the Tax Cuts and Jobs Act		$ 0.0		$ 0.0	$ 9.5
Global intangible low-taxed income		0.0		6.1	68.2
AMT tax credit received		46.9
Deferred tax assets, operating loss carryforwards, foreign		15.0				$ 2.1
Reduction of operating loss carryforwards			$ 1.3
Deferred tax assets, operating loss carryforwards, domestic		2,800.0
Tax credit carryforward, amount		1,400.0
Deferred tax assets, operating loss carryforwards, foreign, net		590.8
Deferred tax assets, operating loss carryforwards, domestic, net		580.3
Deferred tax assets, operating loss carryforwards, state and local		76.3
Deferred tax assets, tax credit carryforwards, general business		112.6
Valuation allowance, income tax		(2,287.3)		(2,068.4)
Unrecognized tax benefits, period increase (decrease)		(7.4)
Net unrecognized tax benefits		9.1		16.5
Unrecognized tax benefits, gross interest and penalties (reversal)		(0.4)		0.4	$ 0.4
Unrecognized tax benefits, accrued gross interest and penalties		5.4		$ 5.8
Decrease in unrecognized tax benefits during the next twelve months		2.2
Scenario, Forecast
Investments, Owned, Federal Income Tax Note [Line Items]
AMT tax credit received	$ 1.2
U.S. — federal
Investments, Owned, Federal Income Tax Note [Line Items]
Valuation allowance, income tax		(1,200.0)
Non-U.S.
Investments, Owned, Federal Income Tax Note [Line Items]
Valuation allowance, income tax		$ (1,100.0)