Derivatives - Derivative Balance Sheet Classification (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 10,437	$ 6,269
Fair Value	7	0
Asset Derivatives	51	60
Liability Derivatives	(44)	(60)
Available-for-sale Securities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	530	588
Fair Value	0	0
Asset Derivatives	0	0
Liability Derivatives	0	0
Investments, Other
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	550	1,695
Fair Value	(7)	20
Asset Derivatives	11	55
Liability Derivatives	(18)	(35)
Liabilities, Other
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	9,357	3,986
Fair Value	14	(20)
Asset Derivatives	40	5
Liability Derivatives	(26)	(25)
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,657	1,906
Fair Value	(3)	(2)
Asset Derivatives	19	27
Liability Derivatives	(22)	(29)
Interest rate swaps \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,250	3,775
Fair Value	0	(1)
Asset Derivatives	1	0
Liability Derivatives	(1)	(1)
Interest rate swaps \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	333	333
Foreign currency swaps \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	530	588
Fair Value	10	3
Asset Derivatives	31	33
Liability Derivatives	(21)	(30)
Total cash flow hedges
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,780	4,363
Fair Value	10	2
Asset Derivatives	32	33
Liability Derivatives	(22)	(31)
Interest rate swaps and futures \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,158	333
Fair Value	(3)	(2)
Asset Derivatives	1	0
Liability Derivatives	(4)	(2)
Foreign currency swaps \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	530	588
Fair Value	0	0
Asset Derivatives	0	0
Liability Derivatives	0	0
Credit derivatives in offsetting positions \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	969	985
Fair Value	0	0
Asset Derivatives	18	27
Liability Derivatives	$ (18)	$ (27)

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value of the assets less the liabilities of a derivative or group of derivatives.

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Nominal or face amount used to calculate payment on derivative.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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