Commitments, Contingencies, And Guarantees (Narrative) (Detail) SFr in Thousands, € in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2026 USD ($)	Mar. 31, 2025 USD ($)	Mar. 31, 2026 EUR (€)	Mar. 17, 2026 CHF (SFr)	Dec. 31, 2025 USD ($)
Financial Instruments Owned and Pledged as Collateral [Line Items]
Derivative Liability, Subject to Master Netting Arrangement, after Offset	$ 112				$ 179
Repurchase agreements	3,736				3,324
Carrying value of limited partnerships and partially-owned investment companies included in other investments	16,800				16,900
Operating Lease, Right-of-Use Asset	1,001				1,025
Operating Lease, Liability	$ 1,231				$ 1,214
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Other liabilities		Other liabilities		Other liabilities
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets (includes VIE balances of $82 and $58)		Other assets (includes VIE balances of $82 and $58)		Other assets (includes VIE balances of $82 and $58)
Private Equity Funds [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Funding commitments relating to limited partnerships and partially-owned investment companies	$ 7,300				$ 7,200
Fair Value Hedging
Financial Instruments Owned and Pledged as Collateral [Line Items]
Hedged Liability, Fair Value Hedge	2,000		€ 1,700
Bonds | Net Investment Hedging | Designated as Hedging Instrument
Financial Instruments Owned and Pledged as Collateral [Line Items]
Notional Amount of Nonderivative Instruments	652
Loans | Net Investment Hedging | Designated as Hedging Instrument
Financial Instruments Owned and Pledged as Collateral [Line Items]
Notional Amount of Nonderivative Instruments	578
Unsecured Debt | Net Investment Hedging | Designated as Hedging Instrument
Financial Instruments Owned and Pledged as Collateral [Line Items]
Notional Amount of Nonderivative Instruments	256
Currency Swap [Member] | Designated as Hedging Instrument
Financial Instruments Owned and Pledged as Collateral [Line Items]
Derivative, Notional Amount	5,981				5,041
Currency Swap [Member] | Net Investment Hedging | Designated as Hedging Instrument
Financial Instruments Owned and Pledged as Collateral [Line Items]
OCI, before Reclassifications, before Tax, Attributable to Parent	58	$ 24
Derivative Notional Amount Terminated | SFr				SFr 95,800
Derivative, Notional Amount	3,891				2,995
OCI, before Reclassifications, before Tax, Attributable to Parent	58	24
Derivative Notional Amount Terminated | SFr				SFr 95,800
Currency Swap [Member] | Fair Value Hedging | Designated as Hedging Instrument
Financial Instruments Owned and Pledged as Collateral [Line Items]
OCI, before Reclassifications, before Tax, Attributable to Parent	(43)	(26)
Derivative, Notional Amount	2,090				$ 2,046
OCI, before Reclassifications, before Tax, Attributable to Parent	$ (43)	$ (26)