Derivatives (Primary Risks) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 321,088		$ 321,088		$ 308,215
Estimated Fair Value Assets	11,583		11,583		10,466
Estimated Fair Value Liabilities	6,855		6,855		$ 3,852
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net	4	$ 1	$ 2	$ (1)
Maximum Length of Time Hedged in Cash Flow Hedge			7 years		7 years
Accumulated Other Comprehensive Income Loss	2,300		$ 2,300		$ 2,100
Derivatives Designated as Hedging Instruments:
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	64,324		64,324		61,088
Estimated Fair Value Assets	5,281		5,281		4,009
Estimated Fair Value Liabilities	3,363		3,363		1,764
Derivatives Designated as Hedging Instruments: | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,602		6,602		5,987
Estimated Fair Value Assets	1,764		1,764		2,175
Estimated Fair Value Liabilities	467		467		87
Derivatives Designated as Hedging Instruments: | Fair Value Hedges [Member] | Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4,331		4,331		3,550
Estimated Fair Value Assets	1,683		1,683		2,164
Estimated Fair Value Liabilities	313		313		6
Derivatives Designated as Hedging Instruments: | Fair Value Hedges [Member] | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	735		735		801
Estimated Fair Value Assets	81		81		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	154		154		58
Derivatives Designated as Hedging Instruments: | Cash Flow Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	54,473		54,473		52,101
Estimated Fair Value Assets	3,173		3,173		1,695
Estimated Fair Value Liabilities	2,896		2,896		1,677
Derivatives Designated as Hedging Instruments: | Cash Flow Hedges [Member] | Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,778		3,778		4,117
Estimated Fair Value Assets	14		14		6
Estimated Fair Value Liabilities	0		0		1
Derivatives Designated as Hedging Instruments: | Cash Flow Hedges [Member] | Interest rate forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	8,042		8,042		6,889
Estimated Fair Value Assets	0		0		89
Estimated Fair Value Liabilities	958		958		119
Derivatives Designated as Hedging Instruments: | Cash Flow Hedges [Member] | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	42,653		42,653		41,095
Estimated Fair Value Assets	3,159		3,159		1,600
Estimated Fair Value Liabilities	1,938		1,938		1,557
Derivatives Designated as Hedging Instruments: | Foreign Operations Hedges [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,249		3,249		3,000
Estimated Fair Value Assets	344		344		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	249		249		0
Estimated Fair Value Assets	25		25		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	319		319		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	256,764		256,764		247,127
Estimated Fair Value Assets	6,302		6,302		6,457
Estimated Fair Value Liabilities	3,492		3,492		2,088
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	33,956		33,956		38,860
Estimated Fair Value Assets	2,006		2,006		3,644
Estimated Fair Value Liabilities	887		887		115
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Interest rate forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	450		450		374
Estimated Fair Value Assets	0		0		0
Estimated Fair Value Liabilities	102		102		26
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Interest rate floors
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	8,351		8,351		7,701
Estimated Fair Value Assets	35		35		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	66,410		66,410		65,559
Estimated Fair Value Assets	739		739		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	1,106		1,106		1,615
Estimated Fair Value Assets	1		1		4
Estimated Fair Value Liabilities	7		7		0
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Interest rate options
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	20,304		20,304		11,754
Estimated Fair Value Assets	553		553		493
Estimated Fair Value Liabilities	43		43		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	109		109		4
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Synthetic GICs
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	44,841		44,841		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	13,392		13,392		12,787
Estimated Fair Value Assets	1,426		1,426		768
Estimated Fair Value Liabilities	466		466		614
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	18,043		18,043		16,230
Estimated Fair Value Assets	150		150		36
Estimated Fair Value Liabilities	1,330		1,330		666
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Currency futures
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	727		727		839
Estimated Fair Value Assets	3		3		0
Estimated Fair Value Liabilities	0		0		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	28		28		13
Estimated Fair Value Liabilities	84		84		113
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Credit default swaps — written
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	11,786		11,786		8,626
Estimated Fair Value Assets	35		35		177
Estimated Fair Value Liabilities	84		84		12
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Equity futures
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,592		3,592		4,204
Estimated Fair Value Assets	38		38		12
Estimated Fair Value Liabilities	8		8		5
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Equity index options
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	26,013		26,013		29,743
Estimated Fair Value Assets	1,065		1,065		1,004
Estimated Fair Value Liabilities	360		360		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	17		17		17
Estimated Fair Value Liabilities	12		12		13
Derivatives Not Designated or Not Qualifying as Hedging Instruments: | Equity total return swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,060		3,060		3,025
Estimated Fair Value Assets	206		206		11
Estimated Fair Value Liabilities	$ 0		$ 0		$ 50