Deposits - Types and Sources of the Firm's Deposits (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Deposits [Line Items]
Savings and demand	$ 77,602	$ 77,197
Time	50,327	46,901
Total	127,929	124,098
Private Bank And Online Retail [Member]
Deposits [Line Items]
Savings and demand	61,589	61,166
Time	4,740	4,437
Total	66,329	65,603
Brokered Certificates Of Deposit [Member]
Deposits [Line Items]
Time	32,630	34,905
Total	32,630	34,905
Deposit Sweep Programs [Member]
Deposits [Line Items]
Savings and demand	16,012	16,019
Total	16,012	16,019
Institutional [Member]
Deposits [Line Items]
Savings and demand	1	12
Time	12,957	7,559
Total	$ 12,958	$ 7,571