Business Segments - Net Interest Income (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Total net interest income	$ 516	$ 883
Investment Banking [Member]
Segment Reporting Information [Line Items]
Total net interest income	0	0
Institutional Client Services [Member]
Segment Reporting Information [Line Items]
Total net interest income	203	703
Investing and Lending [Member]
Segment Reporting Information [Line Items]
Total net interest income	243	136
Investment Management [Member]
Segment Reporting Information [Line Items]
Total net interest income	$ 70	$ 44