Stockholders' Equity - Schedule of Shares Repurchased (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
2019 Program
Equity, Class of Treasury Stock [Line Items]
Shares repurchased and retired (in shares)	0	2	2	17
Aggregate value	$ 0	$ 120,000,000	$ 114,000,000	$ 883,000,000
Average price per share (in usd per share)	$ 0	$ 56.78	$ 66.58	$ 50.70
Remaining authorization	$ 503,000,000	$ 617,000,000	$ 503,000,000	$ 617,000,000
2018 Program
Equity, Class of Treasury Stock [Line Items]
Shares repurchased and retired (in shares)				8
Aggregate value				$ 464,000,000
Average price per share (in usd per share)				$ 59.47
Remaining authorization		$ 0		$ 0