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Investments - Net Investment Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net Investment Income [Line Items]
Investment revenue			$ 3,660	$ 3,673
Investment expenses			(370)	(319)
Net investment income	$ 1,209	$ 1,090	3,290	3,354
AFS securities
Net Investment Income [Line Items]
Investment revenue			2,403	2,276
Trading securities
Net Investment Income [Line Items]
Investment revenue			137	139
Equity securities
Net Investment Income [Line Items]
Investment revenue			10	11
Mortgage loans
Net Investment Income [Line Items]
Investment revenue			545	483
Investment funds
Net Investment Income [Line Items]
Investment revenue			242	245
Funds withheld at interest
Net Investment Income [Line Items]
Investment revenue			165	403
Other
Net Investment Income [Line Items]
Investment revenue			$ 158	$ 116
Consolidated Entity Excluding Variable Interest Entities (VIE)
Net Investment Income [Line Items]
Investment revenue	1,323	1,219
Investment expenses	(114)	(129)
Net investment income	1,209	1,090
Consolidated Entity Excluding Variable Interest Entities (VIE) \| AFS securities
Net Investment Income [Line Items]
Investment revenue	776	760
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Trading securities
Net Investment Income [Line Items]
Investment revenue	47	48
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Equity securities
Net Investment Income [Line Items]
Investment revenue	4	4
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Mortgage loans
Net Investment Income [Line Items]
Investment revenue	184	173
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Investment funds
Net Investment Income [Line Items]
Investment revenue	148	96
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Funds withheld at interest
Net Investment Income [Line Items]
Investment revenue	81	106
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Other
Net Investment Income [Line Items]
Investment revenue	$ 83	$ 32