Securities Financing Activities - Gross and Net Amounts of Securities Financing Agreements (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Assets
Securities purchased under resale agreements, Gross amounts	$ 738,344	$ 618,516
Securities purchased under resale agreements, Amounts netted on the Consolidated balance sheets	(255,640)	(282,090)
Securities purchased under resale agreements, Amounts presented on the Consolidated balance sheets	482,704	336,426
Securities purchased under resale agreements, Amounts not nettable on the Consolidated balance sheets	(472,330)	(324,217)
Securities purchased under resale agreements, Net amounts	10,374	12,209
Securities borrowed, Gross amounts	349,884	357,361
Securities borrowed, Amounts netted on the Consolidated balance sheets	(65,360)	(71,170)
Securities borrowed, Amounts presented on the Consolidated balance sheets	284,524	286,191
Securities borrowed, Amounts not nettable on the Consolidated balance sheets	(234,515)	(234,466)
Security borrowed, Net amounts	50,009	51,725
Liabilities
Securities sold under repurchase agreements, Gross amounts	957,380	715,251
Securities sold under repurchase agreements, Amounts netted on the Consolidated balance sheets	(255,640)	(282,090)
Securities sold under repurchase agreements, Amounts presented on the Consolidated balance sheets	701,740	433,161
Securities sold under repurchase agreements, Amounts not nettable on the Consolidated balance sheets	(664,593)	(397,550)
Securities sold under repurchase agreements, Net amounts	37,147	35,611
Securities loaned and other, Gross amounts	90,719	86,829
Securities loaned and other, Amounts netted on the Consolidated balance sheets	(65,360)	(71,170)
Securities loaned and other, Amounts presented on the Consolidated balance sheets	25,359	15,659
Securities loaned and other, Amounts not nettable on the Consolidated balance sheets	(24,934)	(15,534)
Security loaned and other, Net amounts	425	125
Securities purchased under resale agreements where an appropriate legal opinion with respect to the master netting agreement has not been either sought or obtained	9,000	9,400
Securities borrowed where an appropriate legal opinion with respect to the master netting agreement has not been either sought or obtained	46,000	44,000
Securities sold under agreements to repurchase where an appropriate legal opinion with respect to the master netting agreement has not been either sought or obtained	36,200	34,900
Securities-for-securities
Liabilities
Securities loaned and other, Amounts presented on the Consolidated balance sheets	$ 10,700	$ 6,600