Securities Financing Activities, Contractual Maturities of Gross Obligations (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	$ 371,045	$ 322,482
Securities lending agreements	8,728	7,558
Overnight/Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	227,372	200,118
Securities lending agreements	5,077	3,907
Up to 30 days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	89,910	74,120
Securities lending agreements	0	0
30-90 Days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	29,348	28,270
Securities lending agreements	0	0
Over 90 days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	24,415	19,974
Securities lending agreements	$ 3,651	$ 3,651