Business Segments - Net Interest Income (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Total net interest income	$ 614	$ 842	$ 2,251	$ 2,364
Investment Banking [Member]
Segment Reporting Information [Line Items]
Total net interest income	0	0	0	0
Institutional Client Services [Member]
Segment Reporting Information [Line Items]
Total net interest income	312	665	1,459	1,916
Investing and Lending [Member]
Segment Reporting Information [Line Items]
Total net interest income	235	127	618	318
Investment Management [Member]
Segment Reporting Information [Line Items]
Total net interest income	$ 67	$ 50	$ 174	$ 130