Stockholders’ Equity - Summary of Stock Repurchase Activity (Details) - USD ($)		3 Months Ended		6 Months Ended
	Feb. 13, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jan. 31, 2020
Equity [Abstract]
Shares Repurchased (in shares)				29,000,000
Average Price per Share (in usd per share)				$ 34.30
Value of Shares Repurchased				$ 998,000,000
Shares Repurchased, Remaining Amount Authorized
Beginning balance				2,151,000,000
Authorization of additional plan						$ 5,000,000,000
Repurchase of shares of common stock				(998,000,000)
Ending balance		$ 3,153,000,000		$ 3,153,000,000
Treasury shares retired (in shares)				0
Treasury stock at cost
Equity [Abstract]
Value of Shares Repurchased		0	$ 1,501,000,000	$ 3,550,000,000	$ 3,002,000,000
Shares Repurchased, Remaining Amount Authorized
Repurchase of shares of common stock		0	(1,501,000,000)	(3,550,000,000)	(3,002,000,000)
Additional paid-in capital
Equity [Abstract]
Value of Shares Repurchased		0	0	450,000,000	0
Shares Repurchased, Remaining Amount Authorized
Repurchase of shares of common stock		$ 0	$ 0	$ (450,000,000)	$ 0
Accelerated Share Repurchased Agreement
Equity [Abstract]
Shares Repurchased (in shares)	69,000,000
Value of Shares Repurchased	$ 3,000,000,000.0
Shares Repurchased, Remaining Amount Authorized
Repurchase of shares of common stock	(3,000,000,000.0)
Accelerated Share Repurchased Agreement | Treasury stock at cost
Equity [Abstract]
Shares Repurchased (in shares)				69,000,000
Value of Shares Repurchased	2,550,000,000			$ 2,550,000,000
Shares Repurchased, Remaining Amount Authorized
Repurchase of shares of common stock	(2,550,000,000)			$ (2,550,000,000)
Accelerated Share Repurchased Agreement | Additional paid-in capital
Equity [Abstract]
Shares Repurchased (in shares)				0
Value of Shares Repurchased	450,000,000			$ 450,000,000
Shares Repurchased, Remaining Amount Authorized
Repurchase of shares of common stock	$ (450,000,000)			$ (450,000,000)