Derivatives - Derivative Balance Sheet Classification (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 17,166	$ 10,755
Fair Value	(15)	47
Asset Derivatives	57	62
Liability Derivatives	(72)	(15)
Available-for-sale Securities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	604	569
Fair Value	0	0
Asset Derivatives	0	0
Liability Derivatives	0	0
Other investments
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	15,052	9,108
Fair Value	(45)	34
Asset Derivatives	15	38
Liability Derivatives	(60)	(4)
Other liabilities
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,510	1,078
Fair Value	30	13
Asset Derivatives	42	24
Liability Derivatives	(12)	(11)
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	13,363	8,032
Fair Value	(55)	(6)
Asset Derivatives	8	5
Liability Derivatives	(63)	(11)
Interest rate swaps \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,200	2,155
Fair Value	0	0
Asset Derivatives	1	0
Liability Derivatives	(1)	0
Interest rate swaps \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,600	6,600
Foreign currency swaps \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	603	568
Fair Value	40	53
Asset Derivatives	48	57
Liability Derivatives	(8)	(4)
Total cash flow hedges
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,803	2,723
Fair Value	40	53
Asset Derivatives	49	57
Liability Derivatives	(9)	(4)
Interest rate swaps and futures \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	8,142	7,245
Fair Value	4	(6)
Asset Derivatives	5	2
Liability Derivatives	(1)	(8)
Foreign currency swaps and forwards \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	604	569
Fair Value	0	0
Asset Derivatives	0	0
Liability Derivatives	0	0
Credit derivatives that purchase credit protection \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4,411	11
Fair Value	(59)	0
Asset Derivatives	0	0
Liability Derivatives	(59)	0
Credit derivatives in offsetting positions \| Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	206	207
Fair Value	0	0
Asset Derivatives	3	3
Liability Derivatives	$ (3)	$ (3)

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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