Securities Financing Activities - Types of Financial Assets Pledged and Remaining Maturity (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	$ 1,009,979	$ 715,251
Securities loaned and other	125,394	86,829
Overnight and continuous
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	580,119	406,605
Securities loaned and other	111,723	78,233
Up to 30 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	264,590	168,256
Securities loaned and other	149	1,316
30 – 90 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	32,866	18,169
Securities loaned and other	4,280	976
Greater than 90 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	132,404	122,221
Securities loaned and other	9,242	6,304
Mortgage-backed securities, U.S. GSEs and government agencies
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	142,735	124,776
Securities loaned and other	0	0
Mortgage-backed securities, Residential - nonagency
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	1,271	1,685
Securities loaned and other	0	0
Mortgage-backed securities, Commercial - nonagency
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	298	2,285
Securities loaned and other	0	0
U.S. Treasury, GSEs and government agencies
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	485,384	346,938
Securities loaned and other	5,391	703
Obligations of U.S. states and municipalities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	2,929	1,624
Securities loaned and other	0	0
Non-U.S. government debt
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	208,047	122,346
Securities loaned and other	4,168	1,415
Corporate debt securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	75,670	66,100
Securities loaned and other	6,985	3,433
Asset-backed securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	4,093	6,545
Securities loaned and other	0	0
Equity securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	89,552	42,952
Securities loaned and other	$ 108,850	$ 81,278