Segment, Geographic and Revenue Information - Institutional Securities - Investment Banking Revenues (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue from External Customer [Line Items]
Investment banking	$ 1,758	$ 2,840
Firm Investment banking revenues from contracts with customers (as a percent)	90.00%	92.00%
Institutional Securities | Operating Segments
Revenue from External Customer [Line Items]
Investment banking	$ 1,634	$ 2,613
Institutional Securities | Operating Segments | Advisory
Revenue from External Customer [Line Items]
Investment banking	944	480
Institutional Securities | Operating Segments | Underwriting
Revenue from External Customer [Line Items]
Investment banking	$ 690	$ 2,133