Investments - Loans by Property Type (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	$ 4,233	$ 4,694
Year of Origination 2021
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	670
Year of Origination 2020
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	385	409
Year of Origination 2019
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	356	481
Year of Origination 2018
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	173	288
Year of Origination 2017
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	748	861
Year of Origination 2016
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	518	675
Year of Origination 2015 and prior
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	1,383	1,980
Retail
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	861	1,155
Retail | Year of Origination 2021
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	24
Retail | Year of Origination 2020
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	51	51
Retail | Year of Origination 2019
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	30	32
Retail | Year of Origination 2018
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	35	49
Retail | Year of Origination 2017
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	90	102
Retail | Year of Origination 2016
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	103	129
Retail | Year of Origination 2015 and prior
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	528	792
Industrial
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	1,132	1,188
Industrial | Year of Origination 2021
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	159
Industrial | Year of Origination 2020
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	72	73
Industrial | Year of Origination 2019
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	66	73
Industrial | Year of Origination 2018
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	72	78
Industrial | Year of Origination 2017
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	355	415
Industrial | Year of Origination 2016
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	212	244
Industrial | Year of Origination 2015 and prior
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	196	305
Apartments
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	1,215	1,228
Apartments | Year of Origination 2021
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	368
Apartments | Year of Origination 2020
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	124	141
Apartments | Year of Origination 2019
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	173	283
Apartments | Year of Origination 2018
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	31	124
Apartments | Year of Origination 2017
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	184	204
Apartments | Year of Origination 2016
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	68	138
Apartments | Year of Origination 2015 and prior
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	267	338
Office
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	720	773
Office | Year of Origination 2021
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	104
Office | Year of Origination 2020
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	138	144
Office | Year of Origination 2019
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	67	71
Office | Year of Origination 2018
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	15	17
Office | Year of Origination 2017
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	116	136
Office | Year of Origination 2016
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	127	144
Office | Year of Origination 2015 and prior
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	153	261
Hotel/Motel
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	89	117
Hotel/Motel | Year of Origination 2021
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	0
Hotel/Motel | Year of Origination 2020
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	0	0
Hotel/Motel | Year of Origination 2019
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	20	22
Hotel/Motel | Year of Origination 2018
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	3	3
Hotel/Motel | Year of Origination 2017
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	3	4
Hotel/Motel | Year of Origination 2016
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	0	9
Hotel/Motel | Year of Origination 2015 and prior
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	63	79
Other
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	168	190
Other | Year of Origination 2021
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	7
Other | Year of Origination 2020
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	0	0
Other | Year of Origination 2019
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	0	0
Other | Year of Origination 2018
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	17	17
Other | Year of Origination 2017
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	0	0
Other | Year of Origination 2016
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	5	7
Other | Year of Origination 2015 and prior
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	139	166
Mixed Use
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	48	43
Mixed Use | Year of Origination 2021
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	8
Mixed Use | Year of Origination 2020
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	0	0
Mixed Use | Year of Origination 2019
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	0	0
Mixed Use | Year of Origination 2018
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	0	0
Mixed Use | Year of Origination 2017
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	0	0
Mixed Use | Year of Origination 2016
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	3	4
Mixed Use | Year of Origination 2015 and prior
Investment Holdings [Line Items]
Mortgage loans, before Allowance for Credit Loss	$ 37	$ 39