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Investments (Fixed Maturity Securities Available-For-Sale by Sector) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 307,102		$ 310,811
Allowance for Credit Loss for Debt Securities	(99)	$ (104)	(81)	$ (177)	$ (187)	$ 0
Estimated Fair Value of Fixed Maturity Securities AFS	340,695		354,809
Fixed Maturity Securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gain	35,681		45,519
Gross Unrealized Temporary Loss	1,989		1,440
U.S. corporate
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	80,103		79,788
Allowance for Credit Loss for Debt Securities	(39)	(43)	(44)	(30)	(51)	0
Gross Unrealized Gain	11,557		13,924
Gross Unrealized Temporary Loss	250		252
Estimated Fair Value of Fixed Maturity Securities AFS	91,371		93,416
Foreign government
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	58,674		63,243
Allowance for Credit Loss for Debt Securities	(21)	(21)	(21)	(129)	(136)	0
Gross Unrealized Gain	6,728		8,883
Gross Unrealized Temporary Loss	751		406
Estimated Fair Value of Fixed Maturity Securities AFS	64,630		71,699
Foreign corporate
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	59,400		60,995
Allowance for Credit Loss for Debt Securities	(32)	(33)	(16)	(16)	0	0
Gross Unrealized Gain	6,690		8,897
Gross Unrealized Temporary Loss	453		468
Estimated Fair Value of Fixed Maturity Securities AFS	65,605		69,408
U.S. government and agency
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	41,292		39,094
Allowance for Credit Loss for Debt Securities	0		0
Gross Unrealized Gain	5,599		8,095
Gross Unrealized Temporary Loss	335		89
Estimated Fair Value of Fixed Maturity Securities AFS	46,556		47,100
RMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	28,211		28,415
Allowance for Credit Loss for Debt Securities	0	0	0	(2)	0	0
Gross Unrealized Gain	1,753		2,062
Gross Unrealized Temporary Loss	116		42
Estimated Fair Value of Fixed Maturity Securities AFS	29,848		30,435
ABS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	16,519		16,963
Allowance for Credit Loss for Debt Securities	0		0
Gross Unrealized Gain	224		231
Gross Unrealized Temporary Loss	30		75
Estimated Fair Value of Fixed Maturity Securities AFS	16,713		17,119
Municipals
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	11,439		10,982
Allowance for Credit Loss for Debt Securities	0		0
Gross Unrealized Gain	2,497		2,746
Gross Unrealized Temporary Loss	13		6
Estimated Fair Value of Fixed Maturity Securities AFS	13,923		13,722
CMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	11,464		11,331
Allowance for Credit Loss for Debt Securities	(7)	$ (7)	0	$ 0	$ 0	$ 0
Gross Unrealized Gain	633		681
Gross Unrealized Temporary Loss	41		102
Estimated Fair Value of Fixed Maturity Securities AFS	$ 12,049		$ 11,910