Derivatives and Hedge Accounting - Notional Amounts and Fair Values of Derivative Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Gross Derivative Assets
Notional Amount	$ 3,622	$ 2,337
Fair Value	339	338
Counterparty netting	(143)	(164)
Cash Collateral	(196)	(169)
Derivative assets	0	5
Gross Derivative Liabilities
Notional Amount	3,890	5,073
Fair Value	412	465
Counterparty netting	(143)	(164)
Cash Collateral	(175)	(212)
Total derivative liabilities on consolidated balance sheet	94	89
Bifurcated embedded derivatives assets, fair value	3,000	3,000
Bifurcated embedded derivative liabilities, fair value	0	0
Derivatives designated as hedging instruments | Foreign exchange contracts
Gross Derivative Assets
Notional Amount	547	206
Fair Value	25	21
Gross Derivative Liabilities
Notional Amount	1,087	1,438
Fair Value	86	88
Derivatives not designated as hedging instruments | Foreign exchange contracts
Gross Derivative Assets
Notional Amount	2,113	1,154
Fair Value	71	64
Gross Derivative Liabilities
Notional Amount	1,760	2,576
Fair Value	53	93
Derivatives not designated as hedging instruments | Interest rate contracts
Gross Derivative Assets
Notional Amount	920	935
Fair Value	218	227
Gross Derivative Liabilities
Notional Amount	996	1,012
Fair Value	248	258
Derivatives not designated as hedging instruments | Credit contracts
Gross Derivative Assets
Notional Amount	42	42
Fair Value	25	26
Gross Derivative Liabilities
Notional Amount	47	47
Fair Value	25	26
Derivatives not designated as hedging instruments | Credit contracts | CDS
Gross Derivative Liabilities
Notional Amount	38	38
Fair Value	$ 25	$ 25