Investments (excluding Consolidated Investment Entities) - Loans by Debt Service Coverage Ratio (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	$ 6,830	$ 6,879
>1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	$ 5,201	$ 5,333
Debt Service Coverage Ratio, minimum	150.00%	150.00%
>1.25x - 1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	$ 898	$ 793
Debt Service Coverage Ratio, minimum	125.00%	125.00%
Debt Service Coverage Ratio, maximum	150.00%	150.00%
>1.0x - 1.25x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	$ 457	$ 497
Debt Service Coverage Ratio, minimum	100.00%	100.00%
Debt Service Coverage Ratio, maximum	125.00%	125.00%
Less than 1.0x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	$ 274	$ 256
Debt Service Coverage Ratio, maximum	100.00%	100.00%
Commercial mortgage loans secured by land or construction loans
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	$ 0	$ 0
Year of Origination 2020 [Member]
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	492
Year of Origination 2020 [Member] | >1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	356
Year of Origination 2020 [Member] | >1.25x - 1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	116
Year of Origination 2020 [Member] | >1.0x - 1.25x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	20
Year of Origination 2020 [Member] | Less than 1.0x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	0
Year of Origination 2020 [Member] | Commercial mortgage loans secured by land or construction loans
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	0
Year of Origination 2019 [Member]
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	682	724
Year of Origination 2019 [Member] | >1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	455	493
Year of Origination 2019 [Member] | >1.25x - 1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	108	165
Year of Origination 2019 [Member] | >1.0x - 1.25x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	51	66
Year of Origination 2019 [Member] | Less than 1.0x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	68	0
Year of Origination 2019 [Member] | Commercial mortgage loans secured by land or construction loans
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	0	0
Year of Origination 2018 [Member]
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	442	513
Year of Origination 2018 [Member] | >1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	205	351
Year of Origination 2018 [Member] | >1.25x - 1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	90	13
Year of Origination 2018 [Member] | >1.0x - 1.25x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	92	88
Year of Origination 2018 [Member] | Less than 1.0x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	55	61
Year of Origination 2018 [Member] | Commercial mortgage loans secured by land or construction loans
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	0	0
Year of Origination 2017 [Member]
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	1,077	1,160
Year of Origination 2017 [Member] | >1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	630	608
Year of Origination 2017 [Member] | >1.25x - 1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	243	292
Year of Origination 2017 [Member] | >1.0x - 1.25x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	133	167
Year of Origination 2017 [Member] | Less than 1.0x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	71	93
Year of Origination 2017 [Member] | Commercial mortgage loans secured by land or construction loans
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	0	0
Year of Origination 2016 [Member]
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	942	971
Year of Origination 2016 [Member] | >1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	841	873
Year of Origination 2016 [Member] | >1.25x - 1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	58	63
Year of Origination 2016 [Member] | >1.0x - 1.25x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	40	31
Year of Origination 2016 [Member] | Less than 1.0x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	3	4
Year of Origination 2016 [Member] | Commercial mortgage loans secured by land or construction loans
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	0	0
Year of Origination 2015 [Member]
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	733	805
Year of Origination 2015 [Member] | >1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	685	743
Year of Origination 2015 [Member] | >1.25x - 1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	36	50
Year of Origination 2015 [Member] | >1.0x - 1.25x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	6	6
Year of Origination 2015 [Member] | Less than 1.0x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	6	6
Year of Origination 2015 [Member] | Commercial mortgage loans secured by land or construction loans
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	0	0
Year of Origination 2014 and prior [Member]
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	2,462	2,706
Year of Origination 2014 and prior [Member] | >1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	2,029	2,265
Year of Origination 2014 and prior [Member] | >1.25x - 1.5x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	247	210
Year of Origination 2014 and prior [Member] | >1.0x - 1.25x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	115	139
Year of Origination 2014 and prior [Member] | Less than 1.0x
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	71	92
Year of Origination 2014 and prior [Member] | Commercial mortgage loans secured by land or construction loans
Schedule of Loans by Debt Service Coverage Ratio [Line Items]
Commercial Mortgage Loans	$ 0	$ 0