Stockholder's Equity - Schedule of Shares Repurchased (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
2019 Program
Equity, Class of Treasury Stock [Line Items]
Shares repurchased and retired (in shares)	17
Aggregate value	$ 883
Average price per share (in usd per share)	$ 50.70
Remaining authorization	$ 617
2018 Program
Equity, Class of Treasury Stock [Line Items]
Shares repurchased and retired (in shares)	8	10
Aggregate value	$ 464	$ 536
Average price per share (in usd per share)	$ 59.47	$ 53.46
Remaining authorization	$ 0	$ 464