Trading Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	$ 27,284	$ 28,452
Trading liabilities	5,397	3,235
U.S. Treasury [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	5,145	6,763
US Government agency issued or guaranteed [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	0	18
US Government-sponsored enterprises [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	192	20
Asset-backed securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	143	168
Corporate and foreign bonds [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	7,971	10,826
Equity securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	6,043	5,693
Precious metals [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	4,989	1,909
Trading liabilities	2,312	124
Securities sold, not yet purchased [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading liabilities	727	1,182
Derivatives, net [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	2,801	3,055
Derivatives, net [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading liabilities	$ 2,358	$ 1,929