Investments - Investment Funds (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 723	$ 750
Carrying Amount, Assets, Percent of Total	100.00%	100.00%
Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 4,808	$ 3,550
Carrying Amount, Assets, Percent of Total	100.00%	100.00%
Private equity
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 257	$ 236
Carrying Amount, Assets, Percent of Total	35.50%	31.50%
Private equity | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 257	$ 105
Carrying Amount, Assets, Percent of Total	5.30%	3.00%
Real assets
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 66	$ 83
Carrying Amount, Assets, Percent of Total	9.10%	11.10%
Real assets | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 196	$ 182
Carrying Amount, Assets, Percent of Total	4.10%	5.10%
Real estate
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 290	$ 277
Carrying Amount, Assets, Percent of Total	40.20%	36.90%
Real estate | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 686	$ 853
Carrying Amount, Assets, Percent of Total	14.30%	24.00%
Natural resources
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 0	$ 1
Carrying Amount, Assets, Percent of Total	0.00%	0.10%
Natural resources | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 101	$ 163
Carrying Amount, Assets, Percent of Total	2.10%	4.60%
Other fund | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 272	$ 222
Carrying Amount, Assets, Percent of Total	5.70%	6.30%
Differentiated investments | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 1,935	$ 1,758
Carrying Amount, Assets, Percent of Total	40.30%	49.50%
Credit funds
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 110	$ 153
Carrying Amount, Assets, Percent of Total	15.20%	20.40%
Credit funds | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 373	$ 370
Carrying Amount, Assets, Percent of Total	7.70%	10.40%
Public equities | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 62	$ 119
Carrying Amount, Assets, Percent of Total	1.30%	3.40%
Investments including related party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 5,531	$ 4,300
MidCap | Credit funds | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 0	$ 547
Carrying Amount, Assets, Percent of Total	0.00%	15.40%
AmeriHome | Private equity | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 666	$ 487
Carrying Amount, Assets, Percent of Total	13.90%	13.70%
Catalina Holdings (Bermuda) Ltd [Member] | Private equity | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 317	$ 271
Carrying Amount, Assets, Percent of Total	6.60%	7.60%
Athora Holding Ltd. | Private equity | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 572	$ 132
Carrying Amount, Assets, Percent of Total	11.90%	3.70%
Venerable | Private equity | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 108	$ 99
Carrying Amount, Assets, Percent of Total	2.20%	2.80%
Apollo | Other fund | Related Party
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 1,198	$ 0
Carrying Amount, Assets, Percent of Total	24.90%	0.00%