Deposits - Types and Sources of the Firm's Deposits (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Deposits [Line Items]
Savings and Demand	$ 73,601	$ 54,507
Time	50,949	43,012
Total	124,550	97,519
Private Bank And Online Retail [Member]
Deposits [Line Items]
Savings and Demand	57,700
Time	3,755
Total	61,455
Private Bank Deposits [Member]
Deposits [Line Items]
Savings and Demand		38,715
Time		2,354
Total		41,069
Brokered Certificates Of Deposit [Member]
Deposits [Line Items]
Time	38,812	32,419
Total	38,812	32,419
Deposit Sweep Programs [Member]
Deposits [Line Items]
Savings and Demand	15,900	15,791
Total	15,900	15,791
Institutional [Member]
Deposits [Line Items]
Savings and Demand	1	1
Time	8,382	8,239
Total	$ 8,383	$ 8,240