Variable Interest Entities - Consolidated Variable Interest Entities (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 99,535	$ 75,105	$ 65,575	$ 57,600
Cash and securities segregated for regulatory and other purposes	54,526	56,838
Receivables from brokers, dealers and clearing organizations	25,681	25,453
Loans receivable	49,064	45,407
Financial instruments owned, at fair value	292,420	293,940
Other assets	25,218	25,218
Liabilities
Other secured financings	22,478	24,753
Payables to customers and counterparties	195,625	204,956
Financial instruments sold, but not yet purchased, at fair value	115,154	115,248
Unsecured short-term borrowings	42,825	42,787
Unsecured long-term borrowings	190,586	175,422
Other liabilities and accrued expenses	13,636	18,893
Real Estate, Credit-Related and Other Investing [Member]
Assets
Cash and cash equivalents	386	374
Cash and securities segregated for regulatory and other purposes	34	49
Receivables from brokers, dealers and clearing organizations	1	1
Loans receivable	740	1,534
Financial instruments owned, at fair value	1,893	1,585
Other assets	692	456
Total	3,746	3,999
Liabilities
Other secured financings	318	332
Payables to customers and counterparties	1	2
Financial instruments sold, but not yet purchased, at fair value	10	16
Other liabilities and accrued expenses	796	556
Total	1,125	906
CDOs, Mortgage-Backed and Other Asset-Backed [Member]
Assets
Financial instruments owned, at fair value	251	572
Other assets	6	15
Total	257	587
Liabilities
Other secured financings	141	113
Payables to customers and counterparties		432
Total	141	545
Principal-Protected Notes [Member]
Assets
Financial instruments owned, at fair value	112	126
Total	112	126
Liabilities
Other secured financings	474	413
Unsecured short-term borrowings	381	416
Unsecured long-term borrowings	353	312
Total	1,208	1,141
Consolidated Variable Interest Entity, Total Carrying Amount [Member]
Assets
Cash and cash equivalents	386	374
Cash and securities segregated for regulatory and other purposes	34	49
Receivables from brokers, dealers and clearing organizations	1	1
Loans receivable	740	1,534
Financial instruments owned, at fair value	2,256	2,283
Other assets	698	471
Total	4,115	4,712
Liabilities
Other secured financings	933	858
Payables to customers and counterparties	1	434
Financial instruments sold, but not yet purchased, at fair value	10	16
Unsecured short-term borrowings	381	416
Unsecured long-term borrowings	353	312
Other liabilities and accrued expenses	796	556
Total	$ 2,474	$ 2,592