Investments - Maturities of AFS Securities (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Consolidated Entity Excluding Variable Interest Entities (VIE) and Related Party
Amortized Cost
Due in one year or less	$ 1,164
Due after one year through five years	8,647
Due after five years through ten years	11,125
Due after ten years	18,348
CLO, ABS, CMBS and RMBS	20,460
Amortized Cost	59,744	$ 58,506
Fair Value
Due in one year or less	1,164
Due after one year through five years	8,636
Due after five years through ten years	10,909
Due after ten years	18,169
CLO, ABS, CMBS and RMBS	21,004
Total AFS fixed maturity securities	59,882	61,012
Consolidated Entity Excluding Variable Interest Entities (VIE)
Amortized Cost
Amortized Cost	60,994
Fair Value
Total AFS fixed maturity securities	61,125
Consolidated Entity Excluding Variable Interest Entities (VIE) | Related Party
Amortized Cost
CLO, ABS, CMBS and RMBS	1,250
Amortized Cost	1,250	399
Fair Value
CLO, ABS, CMBS and RMBS	1,243
Total AFS fixed maturity securities	$ 1,243	$ 406