Investment Securities - Components of Non-marketable and Other Equity Securities (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Investment Holdings [Line Items]
Investments in qualified affordable housing projects, net	$ 957	$ 954
Non-marketable and other equity securities	2,605	2,543
Fair value accounting | Consolidated venture capital and private equity fund investments
Investment Holdings [Line Items]
Nonmarketable securities	196	130
Fair value accounting | Unconsolidated venture capital and private equity fund investments
Investment Holdings [Line Items]
Nonmarketable securities	210	208
Fair value accounting | Equity securities
Investment Holdings [Line Items]
Other equity securities in public companies (fair value accounting)	55	117
Fair value accounting | Other investments
Investment Holdings [Line Items]
Nonmarketable securities	169	164
Equity method accounting
Investment Holdings [Line Items]
Nonmarketable securities	721	671
Equity method accounting | Consolidated venture capital and private equity fund investments
Investment Holdings [Line Items]
Nonmarketable securities	721	671
Equity method accounting | Debt funds
Investment Holdings [Line Items]
Nonmarketable securities	5	5
Equity method accounting | Other investments
Investment Holdings [Line Items]
Nonmarketable securities	$ 292	$ 294