Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Effective income tax rate reconciliation (percent)	34.50%	75.80%	34.50%	75.80%
Effective income tax rate reconciliation, including discrete items (percent)	(400.00%)	64.40%	(5.00%)	33.30%
Discrete income tax charge (benefit)	$ (41)	$ 14	$ (39)	$ (23)
Income tax benefit from tax law changes	36		36
Income tax charge (benefit) related to prior year items	(6)	12	(2)	12
Other income tax expense (benefit)	1	$ 2	2	2
Income tax charge for remeasurement related to separation			6
Tax benefit for stock compensation			5
Income tax benefit from deduction of prior year foreign taxes			25
Tax misstatement recorded to retained earnings	$ 258		$ 258		$ 113
Foreign Tax Authority
Income Tax Contingency [Line Items]
Income tax benefit from tax law changes				$ 12
Revision of Prior Period, Error Correction, Adjustment
Income Tax Contingency [Line Items]
Tax misstatement recorded to retained earnings						$ 16