Investments - Loans by Property Type (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Investment Holdings [Line Items]
Commercial mortgage loans	$ 4,194	$ 4,233
Retail
Investment Holdings [Line Items]
Commercial mortgage loans	800	861
Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	1,168	1,132
Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	1,305	1,215
Office
Investment Holdings [Line Items]
Commercial mortgage loans	662	720
Hotel/Motel
Investment Holdings [Line Items]
Commercial mortgage loans	69	89
Other
Investment Holdings [Line Items]
Commercial mortgage loans	142	168
Mixed Use
Investment Holdings [Line Items]
Commercial mortgage loans	48	48
Year of Origination 2020
Investment Holdings [Line Items]
Commercial mortgage loans	314	385
Year of Origination 2020 | Retail
Investment Holdings [Line Items]
Commercial mortgage loans	50	51
Year of Origination 2020 | Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	49	72
Year of Origination 2020 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	91	124
Year of Origination 2020 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	124	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	276	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	58	66
Year of Origination 2019 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	139	173
Year of Origination 2019 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	39	67
Year of Origination 2019 | Hotel/Motel
Investment Holdings [Line Items]
Commercial mortgage loans	11	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	161	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	69	72
Year of Origination 2018 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	30	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	712	748
Year of Origination 2017 | Retail
Investment Holdings [Line Items]
Commercial mortgage loans	89	90
Year of Origination 2017 | Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	338	355
Year of Origination 2017 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	169	184
Year of Origination 2017 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	113	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	1,629	1,901
Year of Origination 2016 | Retail
Investment Holdings [Line Items]
Commercial mortgage loans	552	631
Year of Origination 2016 | Industrial
Investment Holdings [Line Items]
Commercial mortgage loans	308	408
Year of Origination 2016 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	303	335
Year of Origination 2016 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	263	280
Year of Origination 2016 | Hotel/Motel
Investment Holdings [Line Items]
Commercial mortgage loans	45	63
Year of Origination 2016 | Other
Investment Holdings [Line Items]
Commercial mortgage loans	118	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	662	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	146	159
Year of Origination 2021 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	378	368
Year of Origination 2021 | Office
Investment Holdings [Line Items]
Commercial mortgage loans	99	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	440
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	200
Year of Origination 2022 | Apartments
Investment Holdings [Line Items]
Commercial mortgage loans	195
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	10
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