Investments (excluding Consolidated Investment Entities) - Loans by U.S. Region (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Open Option Contracts Written [Line Items]
Commercial mortgage loans	$ 6,904	$ 6,879
Year of Origination 2020
Open Option Contracts Written [Line Items]
Commercial mortgage loans	298	0
Year of Origination 2020 | Pacific
Open Option Contracts Written [Line Items]
Commercial mortgage loans	75	0
Year of Origination 2020 | South Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	138	0
Year of Origination 2020 | Middle Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	17	0
Year of Origination 2020 | West South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	23	0
Year of Origination 2020 | Mountain
Open Option Contracts Written [Line Items]
Commercial mortgage loans	16	0
Year of Origination 2020 | East North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	8	0
Year of Origination 2020 | New England
Open Option Contracts Written [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2020 | West North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2020 | East South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	21	0
Year of Origination 2020 | Total
Open Option Contracts Written [Line Items]
Commercial mortgage loans	298	0
Year of Origination 2019
Open Option Contracts Written [Line Items]
Commercial mortgage loans	714	723
Year of Origination 2019 | Pacific
Open Option Contracts Written [Line Items]
Commercial mortgage loans	99	100
Year of Origination 2019 | South Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	202	200
Year of Origination 2019 | Middle Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	21	35
Year of Origination 2019 | West South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	188	187
Year of Origination 2019 | Mountain
Open Option Contracts Written [Line Items]
Commercial mortgage loans	69	67
Year of Origination 2019 | East North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	65	63
Year of Origination 2019 | New England
Open Option Contracts Written [Line Items]
Commercial mortgage loans	18	18
Year of Origination 2019 | West North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	14	15
Year of Origination 2019 | East South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	38	37
Year of Origination 2019 | Total
Open Option Contracts Written [Line Items]
Commercial mortgage loans	714	722
Year of Origination 2018
Open Option Contracts Written [Line Items]
Commercial mortgage loans	460	513
Year of Origination 2018 | Pacific
Open Option Contracts Written [Line Items]
Commercial mortgage loans	106	106
Year of Origination 2018 | South Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	156	182
Year of Origination 2018 | Middle Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	71	73
Year of Origination 2018 | West South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	38	47
Year of Origination 2018 | Mountain
Open Option Contracts Written [Line Items]
Commercial mortgage loans	59	60
Year of Origination 2018 | East North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	16	16
Year of Origination 2018 | New England
Open Option Contracts Written [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2018 | West North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	14	14
Year of Origination 2018 | East South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	0	15
Year of Origination 2018 | Total
Open Option Contracts Written [Line Items]
Commercial mortgage loans	460	513
Year of Origination 2017
Open Option Contracts Written [Line Items]
Commercial mortgage loans	1,118	1,160
Year of Origination 2017 | Pacific
Open Option Contracts Written [Line Items]
Commercial mortgage loans	175	177
Year of Origination 2017 | South Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	126	128
Year of Origination 2017 | Middle Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	429	464
Year of Origination 2017 | West South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	170	171
Year of Origination 2017 | Mountain
Open Option Contracts Written [Line Items]
Commercial mortgage loans	104	107
Year of Origination 2017 | East North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	63	63
Year of Origination 2017 | New England
Open Option Contracts Written [Line Items]
Commercial mortgage loans	6	6
Year of Origination 2017 | West North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	45	45
Year of Origination 2017 | East South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2017 | Total
Open Option Contracts Written [Line Items]
Commercial mortgage loans	1,118	1,161
Year of Origination 2016
Open Option Contracts Written [Line Items]
Commercial mortgage loans	961	972
Year of Origination 2016 | Pacific
Open Option Contracts Written [Line Items]
Commercial mortgage loans	275	277
Year of Origination 2016 | South Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	178	181
Year of Origination 2016 | Middle Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	189	193
Year of Origination 2016 | West South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	46	47
Year of Origination 2016 | Mountain
Open Option Contracts Written [Line Items]
Commercial mortgage loans	106	107
Year of Origination 2016 | East North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	119	119
Year of Origination 2016 | New England
Open Option Contracts Written [Line Items]
Commercial mortgage loans	14	14
Year of Origination 2016 | West North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	28	28
Year of Origination 2016 | East South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	6	6
Year of Origination 2016 | Total
Open Option Contracts Written [Line Items]
Commercial mortgage loans	961	972
Year of Origination 2015
Open Option Contracts Written [Line Items]
Commercial mortgage loans	746	804
Year of Origination 2015 | Pacific
Open Option Contracts Written [Line Items]
Commercial mortgage loans	210	226
Year of Origination 2015 | South Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	188	218
Year of Origination 2015 | Middle Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	168	171
Year of Origination 2015 | West South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	39	43
Year of Origination 2015 | Mountain
Open Option Contracts Written [Line Items]
Commercial mortgage loans	54	54
Year of Origination 2015 | East North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	64	68
Year of Origination 2015 | New England
Open Option Contracts Written [Line Items]
Commercial mortgage loans	11	12
Year of Origination 2015 | West North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	12	12
Year of Origination 2015 | East South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	0	0
Year of Origination 2015 | Total
Open Option Contracts Written [Line Items]
Commercial mortgage loans	746	804
Year of Origination 2014 and prior
Open Option Contracts Written [Line Items]
Commercial mortgage loans	2,607	2,707
Year of Origination 2014 and prior | Pacific
Open Option Contracts Written [Line Items]
Commercial mortgage loans	708	741
Year of Origination 2014 and prior | South Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	534	553
Year of Origination 2014 and prior | Middle Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	383	390
Year of Origination 2014 and prior | West South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	209	224
Year of Origination 2014 and prior | Mountain
Open Option Contracts Written [Line Items]
Commercial mortgage loans	268	275
Year of Origination 2014 and prior | East North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	234	242
Year of Origination 2014 and prior | New England
Open Option Contracts Written [Line Items]
Commercial mortgage loans	61	67
Year of Origination 2014 and prior | West North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	166	169
Year of Origination 2014 and prior | East South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	44	46
Year of Origination 2014 and prior | Total
Open Option Contracts Written [Line Items]
Commercial mortgage loans	2,607	2,707
Total | Pacific
Open Option Contracts Written [Line Items]
Commercial mortgage loans	1,648	1,627
Total | South Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	1,522	1,462
Total | Middle Atlantic
Open Option Contracts Written [Line Items]
Commercial mortgage loans	1,278	1,326
Total | West South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	713	719
Total | Mountain
Open Option Contracts Written [Line Items]
Commercial mortgage loans	676	670
Total | East North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	569	571
Total | New England
Open Option Contracts Written [Line Items]
Commercial mortgage loans	110	117
Total | West North Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	279	283
Total | East South Central
Open Option Contracts Written [Line Items]
Commercial mortgage loans	109	104
Total | Total
Open Option Contracts Written [Line Items]
Commercial mortgage loans	$ 6,904	$ 6,879