Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Income Taxes [Line Items]
Income tax expense (benefit)	$ 15	$ 249
Income (loss) before income taxes	33	(368)
Net discrete tax adjustments	$ 3	$ 290
U.S. statutory rate	21.00%	21.00%
Non-cash goodwill impairment charge	$ 0	$ 182
Deferred tax asset, tax credit carryforwards, foreign	140		$ 133
Foreign Tax Authority
Income Taxes [Line Items]
Tax credit carryforward, valuation allowance	328	$ 295
Valuation allowance	1,000		1,100
Deferred tax assets	1,200		1,300
Foreign Tax Authority | Luxembourg
Income Taxes [Line Items]
Valuation allowance	$ 923
Foreign Tax Authority | Beginning Year
Income Taxes [Line Items]
Tax credit carryforward expiration year	2025
Foreign Tax Authority | Ending Year
Income Taxes [Line Items]
Tax credit carryforward expiration year	2031
Domestic and State and Local Authority
Income Taxes [Line Items]
Net deferred tax assets	$ 1,200		1,200
Net deferred tax assets, unlimited lives	900
Net deferred tax assets, limited lives	$ 300
Net deferred tax assets, expiration period	between 2025 and 2041
Valuation allowance	$ 368		$ 368