Stockholders' Equity - Additional Information (Details) - USD ($) shares in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity, Class of Treasury Stock [Line Items]
Shares repurchased (shares)			0.0	7.3	0.2
Repurchase of common stock			$ 0	$ 2,274,000,000	$ 42,500,000
Stock repurchase program, remaining authorized amount			717,500,000
Aggregate reduction in common stock and additional paid-in capital during stock repurchases			0	152,000,000	4,100,000
Amount charged to retained earnings during stock repurchases			0	$ 2,122,000,000	38,400,000
Goldman | ASR Program
Equity, Class of Treasury Stock [Line Items]
Shares repurchased (shares)		7.3
Repurchase of common stock	$ 274,000,000	$ 2,000,000,000
Common stock
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount			$ 6,200,000,000.0
Stock Repurchase Program, increased to authorized amount					$ 3,000,000,000