Income Taxes - Textual (Details) $ in Millions, $ in Billions	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2021 AUD ($)
Investments, Owned, Federal Income Tax Note [Line Items]
Global intangible low-taxed income	$ 67.0	$ 0.0	$ 6.1
AMT tax credit received	1.2	46.9
Deferred tax assets, operating loss carryforwards, foreign	15.8			$ 1.6
Deferred tax assets, operating loss carryforwards, domestic	2,600.0
Tax credit carryforward, amount	1,300.0
Deferred tax assets, operating loss carryforwards, foreign, net	491.6
Deferred tax assets, operating loss carryforwards, domestic, net	534.2
Deferred tax assets, operating loss carryforwards, state and local	85.2
Deferred tax assets, tax credit carryforwards, general business	139.1
Valuation allowance, income tax	(2,120.8)	(2,287.3)
Unrecognized tax benefits, period increase (decrease)	1.9
Net unrecognized tax benefits	11.0	9.1
Unrecognized tax benefits, gross interest and penalties (reversal)	0.2	(0.4)	0.4
Unrecognized tax benefits, accrued gross interest and penalties	5.7	$ 5.4	$ 5.8
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	$ (900.0)