Investments - Loans by Property Type (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Investment Holdings [Line Items]
Commercial mortgage loans	$ 4,174	$ 4,233
Retail
Investment Holdings [Line Items]
Commercial mortgage loans	819	861
Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	1,098	1,132
Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	1,287	1,215
Office
Investment Holdings [Line Items]
Commercial mortgage loans	704	720
Hotel/Motel
Investment Holdings [Line Items]
Commercial mortgage loans	75	89
Other
Investment Holdings [Line Items]
Commercial mortgage loans	143	168
Mixed Use
Investment Holdings [Line Items]
Commercial mortgage loans	48	48
Year of Origination 2020
Investment Holdings [Line Items]
Commercial mortgage loans	335	385
Year of Origination 2020 | Retail
Investment Holdings [Line Items]
Commercial mortgage loans	51	51
Year of Origination 2020 | Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	56	72
Year of Origination 2020 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	96	124
Year of Origination 2020 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	132	138
Year of Origination 2020 | Hotel/Motel
Investment Holdings [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2020 | Other
Investment Holdings [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2020 | Mixed Use
Investment Holdings [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2019
Investment Holdings [Line Items]
Commercial mortgage loans	332	356
Year of Origination 2019 | Retail
Investment Holdings [Line Items]
Commercial mortgage loans	29	30
Year of Origination 2019 | Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	65	66
Year of Origination 2019 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	162	173
Year of Origination 2019 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	56	67
Year of Origination 2019 | Hotel/Motel
Investment Holdings [Line Items]
Commercial mortgage loans	20	20
Year of Origination 2019 | Other
Investment Holdings [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2019 | Mixed Use
Investment Holdings [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2018
Investment Holdings [Line Items]
Commercial mortgage loans	163	173
Year of Origination 2018 | Retail
Investment Holdings [Line Items]
Commercial mortgage loans	35	35
Year of Origination 2018 | Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	70	72
Year of Origination 2018 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	31	31
Year of Origination 2018 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	11	15
Year of Origination 2018 | Hotel/Motel
Investment Holdings [Line Items]
Commercial mortgage loans	0	3
Year of Origination 2018 | Other
Investment Holdings [Line Items]
Commercial mortgage loans	16	17
Year of Origination 2018 | Mixed Use
Investment Holdings [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2017
Investment Holdings [Line Items]
Commercial mortgage loans	732	748
Year of Origination 2017 | Retail
Investment Holdings [Line Items]
Commercial mortgage loans	90	90
Year of Origination 2017 | Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	343	355
Year of Origination 2017 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	182	184
Year of Origination 2017 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	114	116
Year of Origination 2017 | Hotel/Motel
Investment Holdings [Line Items]
Commercial mortgage loans	3	3
Year of Origination 2017 | Other
Investment Holdings [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2017 | Mixed Use
Investment Holdings [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2016
Investment Holdings [Line Items]
Commercial mortgage loans	1,673	1,901
Year of Origination 2016 | Retail
Investment Holdings [Line Items]
Commercial mortgage loans	569	631
Year of Origination 2016 | Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	312	408
Year of Origination 2016 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	307	335
Year of Origination 2016 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	274	280
Year of Origination 2016 | Hotel/Motel
Investment Holdings [Line Items]
Commercial mortgage loans	52	63
Year of Origination 2016 | Other
Investment Holdings [Line Items]
Commercial mortgage loans	119	144
Year of Origination 2016 | Mixed Use
Investment Holdings [Line Items]
Commercial mortgage loans	40	40
Year of Origination 2021
Investment Holdings [Line Items]
Commercial mortgage loans	665	670
Year of Origination 2021 | Retail
Investment Holdings [Line Items]
Commercial mortgage loans	23	24
Year of Origination 2021 | Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	148	159
Year of Origination 2021 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	374	368
Year of Origination 2021 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	104	104
Year of Origination 2021 | Hotel/Motel
Investment Holdings [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2021 | Other
Investment Holdings [Line Items]
Commercial mortgage loans	8	7
Year of Origination 2021 | Mixed Use
Investment Holdings [Line Items]
Commercial mortgage loans	8	$ 8
Year of Origination 2022
Investment Holdings [Line Items]
Commercial mortgage loans	274
Year of Origination 2022 | Retail
Investment Holdings [Line Items]
Commercial mortgage loans	22
Year of Origination 2022 | Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	104
Year of Origination 2022 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	135
Year of Origination 2022 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	13
Year of Origination 2022 | Hotel/Motel
Investment Holdings [Line Items]
Commercial mortgage loans	0
Year of Origination 2022 | Other
Investment Holdings [Line Items]
Commercial mortgage loans	0
Year of Origination 2022 | Mixed Use
Investment Holdings [Line Items]
Commercial mortgage loans	$ 0