Derivatives and Hedge Accounting - Notional Amounts and Fair Values of Derivative Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Gross Derivative Assets
Notional Amount	$ 2,638	$ 4,896
Fair Value	388	624
Counterparty netting	(179)	(270)
Cash Collateral	(207)	(304)
Derivative assets	2	50
Gross Derivative Liabilities
Notional Amount	5,497	3,702
Fair Value	444	622
Counterparty netting	(179)	(270)
Cash Collateral	(216)	(201)
Total derivative liabilities on consolidated balance sheet	49	151
Bifurcated embedded derivatives assets, fair value	3,100	3,200
Bifurcated embedded derivative liabilities, fair value	0	0
Derivatives designated as hedging instruments | Foreign exchange contracts
Gross Derivative Assets
Notional Amount	304	879
Fair Value	23	66
Gross Derivative Liabilities
Notional Amount	1,458	906
Fair Value	48	109
Derivatives not designated as hedging instruments | Interest rate contracts
Gross Derivative Assets
Notional Amount	939	841
Fair Value	252	277
Gross Derivative Liabilities
Notional Amount	1,016	913
Fair Value	283	304
Derivatives not designated as hedging instruments | Foreign exchange contracts
Gross Derivative Assets
Notional Amount	1,345	3,095
Fair Value	81	230
Gross Derivative Liabilities
Notional Amount	2,968	1,707
Fair Value	81	158
Derivatives not designated as hedging instruments | Equity contracts
Gross Derivative Assets
Notional Amount	8	29
Fair Value	6	20
Gross Derivative Liabilities
Notional Amount	8	29
Fair Value	6	20
Derivatives not designated as hedging instruments | Credit contracts
Gross Derivative Assets
Notional Amount	42	52
Fair Value	26	31
Gross Derivative Liabilities
Notional Amount	47	147
Fair Value	26	31
Derivatives not designated as hedging instruments | Credit contracts | CDS
Gross Derivative Liabilities
Notional Amount	38	48
Fair Value	$ 25	$ 30