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Investments - Investments - ACL on Mortgages (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning balance			$ 0
Retained earnings					$ (13,503)		$ (12,685)
Financing Receivable, Allowance for Credit Loss			0				0
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	$ (43)	$ 0	0	$ (1)
Financing Receivable, Allowance for Credit Loss	(43)	0	(38)	0	$ (38)		$ 0
Current period provision	(5)	0	19	(1)
Ending balance	(38)	$ 0	$ (38)	$ 0
Cumulative Effect, Period of Adoption, Adjustment [Member] \| Commercial Loan [Member] \| Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Retained earnings						$ 19
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Retained earnings						(12,667)
Financing Receivable, Allowance for Credit Loss						(19)
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] \| Commercial Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	43
Financing Receivable, Allowance for Credit Loss	$ 43					$ (19)