Derivatives (Primary Risks Managed by Derivatives) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 304,571	$ 277,286
Derivative assets:	6,771	4,118
Derivative liabilities:	5,234	5,248
Derivatives Designated as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4,231	4,278
Derivative assets:	266	439
Derivative liabilities:	88	25
Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	300,340	273,008
Derivative assets:	6,505	3,679
Derivative liabilities:	5,146	5,223
Interest rate swaps | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	18,366	69,303
Derivative assets:	152	131
Derivative liabilities:	253	444
Interest rate swaps | Cash flow hedges: | Derivatives Designated as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	500	500
Derivative assets:	0	9
Derivative liabilities:	4	0
Interest rate floors | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	8,000	8,000
Derivative assets:	1	1
Derivative liabilities:	48	30
Interest rate caps | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,100	7,850
Derivative assets:	5	14
Derivative liabilities:	16	14
Interest rate futures | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	0	171
Derivative assets:	0	0
Derivative liabilities:	0	0
Interest rate options | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	26,800	23,060
Derivative assets:	12	11
Derivative liabilities:	444	371
Interest rate forwards | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	23,598	16,352
Derivative assets:	127	121
Derivative liabilities:	1,317	1,876
Foreign currency swaps | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	587	674
Derivative assets:	75	111
Derivative liabilities:	4	0
Foreign currency swaps | Cash flow hedges: | Derivatives Designated as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,731	3,778
Derivative assets:	266	430
Derivative liabilities:	84	25
Foreign currency forwards | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	303	304
Derivative assets:	1	6
Derivative liabilities:	0	0
Credit default swaps — written | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	468	780
Derivative assets:	11	19
Derivative liabilities:	0	0
Equity futures | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,414	316
Derivative assets:	6	0
Derivative liabilities:	4	1
Equity index options | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	69,495	39,897
Derivative assets:	4,530	1,722
Derivative liabilities:	1,362	1,041
Equity total return swaps | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	145,209	106,301
Derivative assets:	1,585	1,543
Derivative liabilities:	$ 1,698	$ 1,446