Derivatives (Primary Risks) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 327,841		$ 327,841		$ 308,215
Estimated Fair Value Assets	14,193		14,193		10,466
Estimated Fair Value Liabilities	8,185		8,185		$ 3,852
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net	19	$ 6	$ 21	$ 5
Maximum Length of Time Hedged in Cash Flow Hedge			7 years		7 years
Accumulated Other Comprehensive Income Loss	3,900		$ 3,900		$ 2,100
Derivatives Designated as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	64,499		64,499		61,088
Estimated Fair Value Assets	7,101		7,101		4,009
Estimated Fair Value Liabilities	4,436		4,436		1,764
Derivatives Designated as Hedging Instruments: | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,388		6,388		5,987
Estimated Fair Value Assets	1,568		1,568		2,175
Estimated Fair Value Liabilities	627		627		87
Derivatives Designated as Hedging Instruments: | Fair Value Hedges [Member] | Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4,222		4,222		3,550
Estimated Fair Value Assets	1,435		1,435		2,164
Estimated Fair Value Liabilities	447		447		6
Derivatives Designated as Hedging Instruments: | Fair Value Hedges [Member] | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	630		630		801
Estimated Fair Value Assets	133		133		11
Estimated Fair Value Liabilities	0		0		23
Derivatives Designated as Hedging Instruments: | Fair Value Hedges [Member] | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,536		1,536		1,636
Estimated Fair Value Assets	0		0		0
Estimated Fair Value Liabilities	180		180		58
Derivatives Designated as Hedging Instruments: | Cash Flow Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	54,866		54,866		52,101
Estimated Fair Value Assets	5,162		5,162		1,695
Estimated Fair Value Liabilities	3,809		3,809		1,677
Derivatives Designated as Hedging Instruments: | Cash Flow Hedges [Member] | Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4,107		4,107		4,117
Estimated Fair Value Assets	6		6		6
Estimated Fair Value Liabilities	43		43		1
Derivatives Designated as Hedging Instruments: | Cash Flow Hedges [Member] | Interest rate forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	8,241		8,241		6,889
Estimated Fair Value Assets	0		0		89
Estimated Fair Value Liabilities	1,221		1,221		119
Derivatives Designated as Hedging Instruments: | Cash Flow Hedges [Member] | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	42,518		42,518		41,095
Estimated Fair Value Assets	5,156		5,156		1,600
Estimated Fair Value Liabilities	2,545		2,545		1,557
Derivatives Designated as Hedging Instruments: | Foreign Operations Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,245		3,245		3,000
Estimated Fair Value Assets	371		371		139
Estimated Fair Value Liabilities	0		0		0
Derivatives Designated as Hedging Instruments: | Foreign Operations Hedges [Member] | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	245		245		0
Estimated Fair Value Assets	33		33		0
Estimated Fair Value Liabilities	0		0		0
Derivatives Designated as Hedging Instruments: | Foreign Operations Hedges [Member] | Currency options
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,000		3,000		3,000
Estimated Fair Value Assets	338		338		139
Estimated Fair Value Liabilities	0		0		0
Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	263,342		263,342		247,127
Estimated Fair Value Assets	7,092		7,092		6,457
Estimated Fair Value Liabilities	3,749		3,749		2,088
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	32,464		32,464		38,860
Estimated Fair Value Assets	1,712		1,712		3,644
Estimated Fair Value Liabilities	1,116		1,116		115
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Interest rate forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	647		647		374
Estimated Fair Value Assets	0		0		0
Estimated Fair Value Liabilities	139		139		26
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Interest rate floors
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	17,071		17,071		7,701
Estimated Fair Value Assets	60		60		145
Estimated Fair Value Liabilities	0		0		0
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Interest rate caps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	65,409		65,409		65,559
Estimated Fair Value Assets	1,063		1,063		124
Estimated Fair Value Liabilities	0		0		0
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Interest rate futures
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,394		1,394		1,615
Estimated Fair Value Assets	2		2		4
Estimated Fair Value Liabilities	6		6		0
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Interest rate options
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	23,885		23,885		11,754
Estimated Fair Value Assets	641		641		493
Estimated Fair Value Liabilities	45		45		10
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Equity total return swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,048		1,048		1,048
Estimated Fair Value Assets	0		0		9
Estimated Fair Value Liabilities	99		99		4
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Synthetic GICs
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	45,066		45,066		40,121
Estimated Fair Value Assets	0		0		0
Estimated Fair Value Liabilities	0		0		0
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	13,002		13,002		12,787
Estimated Fair Value Assets	1,974		1,974		768
Estimated Fair Value Liabilities	509		509		614
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	16,565		16,565		16,230
Estimated Fair Value Assets	217		217		36
Estimated Fair Value Liabilities	1,346		1,346		666
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Currency futures
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	665		665		839
Estimated Fair Value Assets	0		0		0
Estimated Fair Value Liabilities	4		4		2
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Currency options
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	0		0		900
Estimated Fair Value Assets	0		0		0
Estimated Fair Value Liabilities	0		0		0
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Credit default swaps — purchased
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,993		2,993		3,042
Estimated Fair Value Assets	32		32		13
Estimated Fair Value Liabilities	79		79		113
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Credit default swaps — written
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	13,059		13,059		8,626
Estimated Fair Value Assets	78		78		177
Estimated Fair Value Liabilities	89		89		12
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Equity futures
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,966		2,966		4,204
Estimated Fair Value Assets	29		29		12
Estimated Fair Value Liabilities	5		5		5
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Equity index options
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	23,431		23,431		29,743
Estimated Fair Value Assets	1,076		1,076		1,004
Estimated Fair Value Liabilities	299		299		458
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Equity variance swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	692		692		699
Estimated Fair Value Assets	18		18		17
Estimated Fair Value Liabilities	13		13		13
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Equity total return swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,985		2,985		3,025
Estimated Fair Value Assets	190		190		11
Estimated Fair Value Liabilities	$ 0		$ 0		$ 50