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Investments (Fixed Maturity Securities Available-For-Sale by Sector) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 310,004		$ 310,811
Allowance for Credit Loss for Debt Securities	(68)	$ (99)	(81)	$ (75)	$ (177)	$ 0
Gross Unrealized Gains	33,349		45,519
Gross Unrealized Losses	2,247		1,440
Estimated Fair Value of Fixed Maturity Securities AFS	341,038		354,809
U.S. corporate
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	81,187		79,788
Allowance for Credit Loss for Debt Securities	(18)	(39)	(44)	(30)	(30)	0
Gross Unrealized Gains	11,110		13,924
Gross Unrealized Losses	267		252
Estimated Fair Value of Fixed Maturity Securities AFS	92,012		93,416
Foreign government
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	57,889		63,243
Allowance for Credit Loss for Debt Securities	(19)	(21)	(21)	(29)	(129)	0
Gross Unrealized Gains	6,273		8,883
Gross Unrealized Losses	763		406
Estimated Fair Value of Fixed Maturity Securities AFS	63,380		71,699
Foreign corporate
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	58,918		60,995
Allowance for Credit Loss for Debt Securities	(24)	(32)	(16)	(16)	(16)	0
Gross Unrealized Gains	5,674		8,897
Gross Unrealized Losses	646		468
Estimated Fair Value of Fixed Maturity Securities AFS	63,922		69,408
U.S. government and agency
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	43,072		39,094
Allowance for Credit Loss for Debt Securities	0		0
Gross Unrealized Gains	5,396		8,095
Gross Unrealized Losses	368		89
Estimated Fair Value of Fixed Maturity Securities AFS	48,100		47,100
RMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	28,716		28,415
Allowance for Credit Loss for Debt Securities	0	0	0	0	(2)	0
Gross Unrealized Gains	1,669		2,062
Gross Unrealized Losses	118		42
Estimated Fair Value of Fixed Maturity Securities AFS	30,267		30,435
ABS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	17,203		16,963
Allowance for Credit Loss for Debt Securities	0		0
Gross Unrealized Gains	227		231
Gross Unrealized Losses	27		75
Estimated Fair Value of Fixed Maturity Securities AFS	17,403		17,119
Municipals
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	11,636		10,982
Allowance for Credit Loss for Debt Securities	0		0
Gross Unrealized Gains	2,419		2,746
Gross Unrealized Losses	15		6
Estimated Fair Value of Fixed Maturity Securities AFS	14,040		13,722
CMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	11,383		11,331
Allowance for Credit Loss for Debt Securities	(7)	$ (7)	0	$ 0	$ 0	$ 0
Gross Unrealized Gains	581		681
Gross Unrealized Losses	43		102
Estimated Fair Value of Fixed Maturity Securities AFS	$ 11,914		$ 11,910