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Derivatives (Primary Risks) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 301,234	$ 328,116
Estimated Fair Value Assets	8,737	11,411
Estimated Fair Value Liabilities	6,298	6,975
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	64,155	63,923
Estimated Fair Value Assets	4,215	5,244
Estimated Fair Value Liabilities	3,320	3,909
Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,475	6,081
Estimated Fair Value Assets	1,312	1,445
Estimated Fair Value Liabilities	600	556
Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedges [Member] | Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4,550	4,143
Estimated Fair Value Assets	1,257	1,353
Estimated Fair Value Liabilities	535	467
Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedges [Member] | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,475	602
Estimated Fair Value Assets	55	82
Estimated Fair Value Liabilities	0	0
Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedges [Member] | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	450	1,336
Estimated Fair Value Assets	0	10
Estimated Fair Value Liabilities	65	89
Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	54,177	54,162
Estimated Fair Value Assets	2,509	3,563
Estimated Fair Value Liabilities	2,712	3,315
Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedges [Member] | Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4,156	4,107
Estimated Fair Value Assets	1	8
Estimated Fair Value Liabilities	265	262
Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedges [Member] | Interest rate forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,115	7,447
Estimated Fair Value Assets	51	1
Estimated Fair Value Liabilities	938	1,354
Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedges [Member] | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	43,906	42,608
Estimated Fair Value Assets	2,457	3,554
Estimated Fair Value Liabilities	1,509	1,699
Derivatives Designated as Hedging Instruments [Member] | Foreign Operations Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,503	3,680
Estimated Fair Value Assets	394	236
Estimated Fair Value Liabilities	8	38
Derivatives Designated as Hedging Instruments [Member] | Foreign Operations Hedges [Member] | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	503	680
Estimated Fair Value Assets	0	0
Estimated Fair Value Liabilities	8	38
Derivatives Designated as Hedging Instruments [Member] | Foreign Operations Hedges [Member] | Currency options
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,000	3,000
Estimated Fair Value Assets	394	236
Estimated Fair Value Liabilities	0	0
Not Designated as Hedging Instrument, Economic Hedge | Derivative Contract [Domain]
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(596)	(640)
Not Designated as Hedging Instrument, Economic Hedge | Interest rate
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	9,096	9,098
Estimated Fair Value Assets	13	41
Estimated Fair Value Liabilities	663	764
Not Designated as Hedging Instrument, Economic Hedge | Foreign currency exchange rate
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	716	887
Estimated Fair Value Assets	22	26
Estimated Fair Value Liabilities	2	2
Not Designated as Hedging Instrument, Economic Hedge | Equity
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	5,189	8,829
Estimated Fair Value Assets	77	233
Estimated Fair Value Liabilities	373	381
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	237,079	264,193
Estimated Fair Value Assets	4,522	6,167
Estimated Fair Value Liabilities	2,978	3,066
Derivative, Gain (Loss) on Derivative, Net	(3,234)	(3,401)	$ (4,305)
Not Designated as Hedging Instrument [Member] | Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	29,801	31,661
Estimated Fair Value Assets	1,497	1,660
Estimated Fair Value Liabilities	1,102	1,354
Not Designated as Hedging Instrument [Member] | Interest rate forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,383	381
Estimated Fair Value Assets	69	0
Estimated Fair Value Liabilities	36	32
Not Designated as Hedging Instrument [Member] | Interest rate floors
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	15,321	25,270
Estimated Fair Value Assets	41	125
Estimated Fair Value Liabilities	0	0
Not Designated as Hedging Instrument [Member] | Interest rate caps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	30,016	48,290
Estimated Fair Value Assets	373	950
Estimated Fair Value Liabilities	0	0
Not Designated as Hedging Instrument [Member] | Interest rate futures
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,243	1,453
Estimated Fair Value Assets	1	2
Estimated Fair Value Liabilities	5	1
Not Designated as Hedging Instrument [Member] | Interest rate options
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	43,926	44,391
Estimated Fair Value Assets	385	473
Estimated Fair Value Liabilities	103	88
Not Designated as Hedging Instrument [Member] | Synthetic GICs
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	49,066	46,316
Estimated Fair Value Assets	0	0
Estimated Fair Value Liabilities	0	0
Not Designated as Hedging Instrument [Member] | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	11,891	12,815
Estimated Fair Value Assets	1,200	1,454
Estimated Fair Value Liabilities	356	383
Not Designated as Hedging Instrument [Member] | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	14,128	16,195
Estimated Fair Value Assets	310	544
Estimated Fair Value Liabilities	806	661
Not Designated as Hedging Instrument [Member] | Currency futures
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	314	333
Estimated Fair Value Assets	2	8
Estimated Fair Value Liabilities	0	0
Not Designated as Hedging Instrument [Member] | Currency options
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	50	0
Estimated Fair Value Assets	0	0
Estimated Fair Value Liabilities	0	0
Not Designated as Hedging Instrument [Member] | Credit default swaps — purchased
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,877	2,925
Estimated Fair Value Assets	3	18
Estimated Fair Value Liabilities	79	79
Not Designated as Hedging Instrument [Member] | Credit default swaps — written
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	12,468	11,512
Estimated Fair Value Assets	233	133
Estimated Fair Value Liabilities	5	28
Not Designated as Hedging Instrument [Member] | Equity futures
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,163	2,988
Estimated Fair Value Assets	8	8
Estimated Fair Value Liabilities	11	4
Not Designated as Hedging Instrument [Member] | Equity index options
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	19,421	16,701
Estimated Fair Value Assets	399	765
Estimated Fair Value Liabilities	255	323
Not Designated as Hedging Instrument [Member] | Equity variance swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	99	163
Estimated Fair Value Assets	0	4
Estimated Fair Value Liabilities	2	1
Not Designated as Hedging Instrument [Member] | Equity Total Return Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,912	2,799
Estimated Fair Value Assets	1	23
Estimated Fair Value Liabilities	218	112
Not Designated as Hedging Instrument [Member] | Derivatives hedging MRBs
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	15,001	18,814
Estimated Fair Value Assets	112	300
Estimated Fair Value Liabilities	$ 1,038	$ 1,147

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