Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Effective income tax rate reconciliation, percent			43.90%	26.50%
Effective income tax rate reconciliation, including discrete items, percent	54.50%	35.30%	40.60%	34.00%
Discrete income tax charge	$ 10	$ 26	$ (25)	$ 49
Change in prior year taxes	9		9
Interest accruals for potential underpayment of taxes	2		2
Change in deferred tax assets valuation allowance	(1)		(13)
Charge related to establishing tax reserve		59		59
Prior year adjustments related to a change in jurisdiction		13		13
Income tax benefit from reversal of foreign tax reserve	$ 38		(25)	38
Tax charge (benefit) from reduction in estimate of the then provisional impact of the Tax Cut and Jobs Act of 2017		$ (8)		13
Income tax charge for a number of small items			$ 2
Income tax charge related to stock compensation				$ 2