Investments (excluding Consolidated Investment Entities) - Unrealized Capital Losses (Details) $ in Millions	Mar. 31, 2023 USD ($) security	Dec. 31, 2022 USD ($) security
Available-for-sale Securities, Including Securities Pledged [Line Items]
Twelve months or less below amortized cost, Fair Value	$ 11,829	$ 20,391
Twelve months or less below amortized cost, Unrealized Capital Loss	$ 739	$ 2,349
Twelve months or less below amortized cost, total number of securities in an unrealized loss position | security	2,040	3,633
More than twelve months below amortized cost, Fair Value	$ 11,382	$ 4,363
More than twelve months below amortized cost, Unrealized Capital Loss	$ 2,199	$ 1,132
More than twelve months below amortized cost, total number of securities in an unrealized loss position | security	2,563	1,187
Total, Fair Value	$ 23,211	$ 24,754
Total Unrealized Capital Losses	$ 2,938	$ 3,481
Total, Number of securities | security	4,603	4,820
U.S. Treasuries
Available-for-sale Securities, Including Securities Pledged [Line Items]
Twelve months or less below amortized cost, Fair Value	$ 106	$ 197
Twelve months or less below amortized cost, Unrealized Capital Loss	$ 1	$ 19
Twelve months or less below amortized cost, total number of securities in an unrealized loss position | security	10	19
More than twelve months below amortized cost, Fair Value	$ 47	$ 9
More than twelve months below amortized cost, Unrealized Capital Loss	$ 10	$ 2
More than twelve months below amortized cost, total number of securities in an unrealized loss position | security	13	7
Total, Fair Value	$ 153	$ 206
Total Unrealized Capital Losses	$ 11	$ 21
Total, Number of securities | security	23	26
State, municipalities and political subdivisions
Available-for-sale Securities, Including Securities Pledged [Line Items]
Twelve months or less below amortized cost, Fair Value	$ 573	$ 751
Twelve months or less below amortized cost, Unrealized Capital Loss	$ 44	$ 121
Twelve months or less below amortized cost, total number of securities in an unrealized loss position | security	206	284
More than twelve months below amortized cost, Fair Value	$ 209	$ 30
More than twelve months below amortized cost, Unrealized Capital Loss	$ 54	$ 13
More than twelve months below amortized cost, total number of securities in an unrealized loss position | security	82	17
Total, Fair Value	$ 782	$ 781
Total Unrealized Capital Losses	$ 98	$ 134
Total, Number of securities | security	288	301
U.S. corporate public securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Twelve months or less below amortized cost, Fair Value	$ 3,181	$ 5,479
Twelve months or less below amortized cost, Unrealized Capital Loss	$ 220	$ 792
Twelve months or less below amortized cost, total number of securities in an unrealized loss position | security	558	1,054
More than twelve months below amortized cost, Fair Value	$ 2,864	$ 1,137
More than twelve months below amortized cost, Unrealized Capital Loss	$ 778	$ 447
More than twelve months below amortized cost, total number of securities in an unrealized loss position | security	733	347
Total, Fair Value	$ 6,045	$ 6,616
Total Unrealized Capital Losses	$ 998	$ 1,239
Total, Number of securities | security	1,291	1,401
U.S. corporate private securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Twelve months or less below amortized cost, Fair Value	$ 2,268	$ 3,569
Twelve months or less below amortized cost, Unrealized Capital Loss	$ 113	$ 322
Twelve months or less below amortized cost, total number of securities in an unrealized loss position | security	243	375
More than twelve months below amortized cost, Fair Value	$ 1,552	$ 458
More than twelve months below amortized cost, Unrealized Capital Loss	$ 227	$ 87
More than twelve months below amortized cost, total number of securities in an unrealized loss position | security	152	32
Total, Fair Value	$ 3,820	$ 4,027
Total Unrealized Capital Losses	$ 340	$ 409
Total, Number of securities | security	395	407
Foreign corporate public securities and foreign governments
Available-for-sale Securities, Including Securities Pledged [Line Items]
Twelve months or less below amortized cost, Fair Value	$ 1,185	$ 2,050
Twelve months or less below amortized cost, Unrealized Capital Loss	$ 76	$ 260
Twelve months or less below amortized cost, total number of securities in an unrealized loss position | security	205	371
More than twelve months below amortized cost, Fair Value	$ 1,008	$ 391
More than twelve months below amortized cost, Unrealized Capital Loss	$ 255	$ 143
More than twelve months below amortized cost, total number of securities in an unrealized loss position | security	230	97
Total, Fair Value	$ 2,193	$ 2,441
Total Unrealized Capital Losses	$ 331	$ 403
Total, Number of securities | security	435	468
Foreign corporate private securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Twelve months or less below amortized cost, Fair Value	$ 1,834	$ 2,728
Twelve months or less below amortized cost, Unrealized Capital Loss	$ 75	$ 211
Twelve months or less below amortized cost, total number of securities in an unrealized loss position | security	138	217
More than twelve months below amortized cost, Fair Value	$ 793	$ 65
More than twelve months below amortized cost, Unrealized Capital Loss	$ 96	$ 14
More than twelve months below amortized cost, total number of securities in an unrealized loss position | security	68	6
Total, Fair Value	$ 2,627	$ 2,793
Total Unrealized Capital Losses	$ 171	$ 225
Total, Number of securities | security	206	223
Residential mortgage-backed
Available-for-sale Securities, Including Securities Pledged [Line Items]
Twelve months or less below amortized cost, Fair Value	$ 782	$ 1,538
Twelve months or less below amortized cost, Unrealized Capital Loss	$ 43	$ 128
Twelve months or less below amortized cost, total number of securities in an unrealized loss position | security	329	536
More than twelve months below amortized cost, Fair Value	$ 964	$ 562
More than twelve months below amortized cost, Unrealized Capital Loss	$ 214	$ 162
More than twelve months below amortized cost, total number of securities in an unrealized loss position | security	447	283
Total, Fair Value	$ 1,746	$ 2,100
Total Unrealized Capital Losses	$ 257	$ 290
Total, Number of securities | security	776	819
Commercial mortgage-backed securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Twelve months or less below amortized cost, Fair Value	$ 1,346	$ 2,628
Twelve months or less below amortized cost, Unrealized Capital Loss	$ 141	$ 390
Twelve months or less below amortized cost, total number of securities in an unrealized loss position | security	213	441
More than twelve months below amortized cost, Fair Value	$ 2,410	$ 1,133
More than twelve months below amortized cost, Unrealized Capital Loss	$ 433	$ 195
More than twelve months below amortized cost, total number of securities in an unrealized loss position | security	438	207
Total, Fair Value	$ 3,756	$ 3,761
Total Unrealized Capital Losses	$ 574	$ 585
Total, Number of securities | security	651	648
Other asset-backed securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Twelve months or less below amortized cost, Fair Value	$ 554	$ 1,430
Twelve months or less below amortized cost, Unrealized Capital Loss	$ 26	$ 104
Twelve months or less below amortized cost, total number of securities in an unrealized loss position | security	138	334
More than twelve months below amortized cost, Fair Value	$ 1,532	$ 578
More than twelve months below amortized cost, Unrealized Capital Loss	$ 131	$ 69
More than twelve months below amortized cost, total number of securities in an unrealized loss position | security	399	191
Total, Fair Value	$ 2,086	$ 2,008
Total Unrealized Capital Losses	$ 157	$ 173
Total, Number of securities | security	537	525
U.S. Government agencies and authorities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Twelve months or less below amortized cost, Fair Value	$ 0	$ 21
Twelve months or less below amortized cost, Unrealized Capital Loss	$ 0	$ 2
Twelve months or less below amortized cost, total number of securities in an unrealized loss position | security	0	2
More than twelve months below amortized cost, Fair Value	$ 3	$ 0
More than twelve months below amortized cost, Unrealized Capital Loss	$ 1	$ 0
More than twelve months below amortized cost, total number of securities in an unrealized loss position | security	1	0
Total, Fair Value	$ 3	$ 21
Total Unrealized Capital Losses	$ 1	$ 2
Total, Number of securities | security	1	2