Business Segments - Net Interest Income (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Total	$ 1,008	$ 856	$ 3,297	$ 2,776
Investment Banking [Member]
Segment Reporting Information [Line Items]
Total	0	0	0	0
Institutional Client Services [Member]
Segment Reporting Information [Line Items]
Total	175	146	803	771
Investing and Lending [Member]
Segment Reporting Information [Line Items]
Total	751	616	2,237	1,741
Investment Management [Member]
Segment Reporting Information [Line Items]
Total	$ 82	$ 94	$ 257	$ 264