Collateralized Agreements and Financings - Schedule of Gross Carrying Value of Repurchase Agreements and Securities Loaned by Class of Collateral Pledged (Detail) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Offsetting Liabilities [Line Items]
Repurchase agreements	$ 529,846	$ 502,148
Securities loaned	71,575	71,581
Money market instruments
Offsetting Liabilities [Line Items]
Repurchase agreements	1,209	395
Securities loaned	0	0
U.S. government and agency obligations
Offsetting Liabilities [Line Items]
Repurchase agreements	281,528	319,406
Securities loaned	191	0
Non-U.S. government obligations
Offsetting Liabilities [Line Items]
Repurchase agreements	200,544	141,625
Securities loaned	1,308	1,416
Securities backed by commercial real estate
Offsetting Liabilities [Line Items]
Repurchase agreements	226	247
Securities loaned	0	0
Securities backed by residential real estate
Offsetting Liabilities [Line Items]
Repurchase agreements	2,719	2,219
Securities loaned	0	0
Corporate debt securities
Offsetting Liabilities [Line Items]
Repurchase agreements	15,688	13,281
Securities loaned	140	186
State and municipal obligations
Offsetting Liabilities [Line Items]
Repurchase agreements	872	370
Securities loaned	0	0
Other debt obligations
Offsetting Liabilities [Line Items]
Repurchase agreements	91	89
Securities loaned	0	0
Equity securities
Offsetting Liabilities [Line Items]
Repurchase agreements	26,969	24,516
Securities loaned	$ 69,936	$ 69,979