Investments (Fixed Maturity Securities Available-For-Sale by Sector) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 302,873		$ 297,655
Amortized cost of fixed maturity securities valuation allowances	(177)	$ (187)	0
Gross Unrealized OTTI Loss	0		33
Debt Securities, Available-for-sale	340,005		327,820
Fixed Maturity Securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gain	40,479		31,812
Gross Unrealized Temporary Loss	3,170		1,680
Gross Unrealized OTTI Loss			(33)
U.S. corporate
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	79,085		79,115
Amortized cost of fixed maturity securities valuation allowances	(30)	(51)	0
Gross Unrealized Gain	11,766		8,943
Gross Unrealized Temporary Loss	709		305
Gross Unrealized OTTI Loss			0
Debt Securities, Available-for-sale	90,112		87,753
Foreign government
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	57,964		58,840
Amortized cost of fixed maturity securities valuation allowances	(129)	(136)	0
Gross Unrealized Gain	8,260		8,710
Gross Unrealized Temporary Loss	389		321
Gross Unrealized OTTI Loss			0
Debt Securities, Available-for-sale	65,706		67,229
Foreign corporate
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	58,346		59,342
Amortized cost of fixed maturity securities valuation allowances	(16)	0	0
Gross Unrealized Gain	5,765		5,540
Gross Unrealized Temporary Loss	1,278		717
Gross Unrealized OTTI Loss			0
Debt Securities, Available-for-sale	62,817		64,165
U.S. government and agency
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	37,915		37,586
Amortized cost of fixed maturity securities valuation allowances	0
Gross Unrealized Gain	9,394		4,604
Gross Unrealized Temporary Loss	22		106
Gross Unrealized OTTI Loss			0
Debt Securities, Available-for-sale	47,287		42,084
RMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	29,963		27,051
Amortized cost of fixed maturity securities valuation allowances	(2)	$ 0	0
Gross Unrealized Gain	1,999		1,535
Gross Unrealized Temporary Loss	85		72
Gross Unrealized OTTI Loss			(33)
Debt Securities, Available-for-sale	31,875		28,547
ABS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	16,603		14,547
Amortized cost of fixed maturity securities valuation allowances	0
Gross Unrealized Gain	127		83
Gross Unrealized Temporary Loss	406		88
Gross Unrealized OTTI Loss			0
Debt Securities, Available-for-sale	16,324		14,542
Municipals
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	11,930		11,081
Amortized cost of fixed maturity securities valuation allowances	0
Gross Unrealized Gain	2,685		2,001
Gross Unrealized Temporary Loss	4		29
Gross Unrealized OTTI Loss			0
Debt Securities, Available-for-sale	14,611		13,053
CMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	11,067		10,093
Amortized cost of fixed maturity securities valuation allowances	0
Gross Unrealized Gain	483		396
Gross Unrealized Temporary Loss	277		42
Gross Unrealized OTTI Loss			0
Debt Securities, Available-for-sale	$ 11,273		$ 10,447

Other-than-temporary impairments on fixed maturity securities transferred to other comprehensive income loss.

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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