Stockholders' Equity - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, remaining authorized amount	$ 1,700,000,000
Aggregate reduction in common stock and additional paid-in capital during stock repurchases	14,500,000	$ 0	$ 152,000,000
Amount charged to retained earnings during stock repurchases	255,000,000	$ 0	$ 2,122,000,000
Common stock
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount	$ 7,500,000,000
Stock Repurchase Program, increased to authorized amount				$ 2,000,000,000.0