Stockholders’ Equity - Summary of Stock Repurchase Activity (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Feb. 28, 2021	Jan. 31, 2020
Equity [Abstract]
Shares Repurchased (in shares)	5,000,000
Average Price per Share (in usd per share)	$ 55.70
Value of Shares Repurchased	$ 292,000,000
Shares Repurchased, Remaining Amount Authorized
Beginning balance	2,033,000,000
Authorization of additional plan		$ 4,000,000,000.0	$ 5,000,000,000.0
Repurchase of shares of common stock	(292,000,000)
Ending balance	$ 5,741,000,000
Treasury shares retired (in shares)	0