Business Segments - Assets by Segment (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total	$ 1,089,756	$ 992,968
Investment Banking [Member]
Segment Reporting Information [Line Items]
Total	105,059	92,009
Global Markets [Member]
Segment Reporting Information [Line Items]
Total	800,476	725,060
Asset Management [Member]
Segment Reporting Information [Line Items]
Total	92,636	92,102
Consumer & Wealth Management [Member]
Segment Reporting Information [Line Items]
Total	$ 91,585	$ 83,797