Derivatives - Derivative Balance Sheet Classification (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 6,757	$ 7,081
Fair Value	31	45
Asset Derivatives	67	88
Liability Derivatives	(36)	(43)
Available-for-sale Securities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	607	647
Fair Value	0	0
Asset Derivatives	0	0
Liability Derivatives	0	0
Other investments
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,177	3,011
Fair Value	36	57
Asset Derivatives	40	66
Liability Derivatives	(4)	(9)
Other liabilities
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4,973	3,423
Fair Value	(5)	(12)
Asset Derivatives	27	22
Liability Derivatives	(32)	(34)
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,926	2,210
Fair Value	(2)	4
Asset Derivatives	23	36
Liability Derivatives	(25)	(32)
Interest rate swaps \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4,225	4,225
Fair Value	0	0
Asset Derivatives	0	0
Liability Derivatives	0	0
Interest rate swaps \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	333	344
Foreign currency swaps \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	606	646
Fair Value	33	41
Asset Derivatives	44	52
Liability Derivatives	(11)	(11)
Total cash flow hedges
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4,831	4,871
Fair Value	33	41
Asset Derivatives	44	52
Liability Derivatives	(11)	(11)
Interest rate swaps and futures \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	333	344
Fair Value	(2)	0
Asset Derivatives	0	1
Liability Derivatives	(2)	(1)
Foreign currency swaps \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	607	647
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	986	986
Fair Value	0	0
Asset Derivatives	23	31
Liability Derivatives	(23)	(31)
Equity Option [Member] \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	0	233
Fair Value	0	4
Asset Derivatives	0	4
Liability Derivatives	$ 0	$ 0

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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- Definition

Fair value, before effects of master netting arrangements, of a financial liability or 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 liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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- Definition

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

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- Definition

Nominal or face amount used to calculate payment on derivative.

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