Fair Value - Financial Instruments Not Carried at Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Assets
Mortgage loans	$ 15,203	$ 14,306
Investment funds	682	750
Policy loans	393	417
Funds withheld at interest	42,269	15,181
Other investments	359	158
Liabilities
Interest sensitive contract liabilities	135,537	102,745
Long-term debt	1,486	992
Funds withheld liability	427	408
Short-term Debt	0	475
Carrying Value
Assets
Mortgage loans	15,178	14,279
Investment funds	536	596
Policy loans	393	417
Funds withheld at interest	41,506	14,380
Other investments	250	65
Short-term investments		190
Total assets measured at fair value	74,767	46,424
Liabilities
Interest sensitive contract liabilities	86,829	57,272
Long-term debt	1,486	992
Securities Sold under Agreements to Repurchase	1,599	512
Funds withheld liability	381	377
Total liabilities not carried at fair value	90,295	59,628
Short-term Debt		475
Fair Value
Assets
Mortgage loans	15,636	14,719
Investment funds	536	596
Policy loans	393	417
Funds withheld at interest	41,506	14,380
Other investments	256	65
Short-term investments		190
Total assets measured at fair value	75,223	46,902
Liabilities
Interest sensitive contract liabilities	90,369	58,027
Long-term debt	1,035	1,036
Securities Sold under Agreements to Repurchase	1,599	512
Funds withheld liability	381	377
Total liabilities not carried at fair value	93,384	60,427
Short-term Debt, Fair Value		475
Level 1 | Fair Value
Assets
Mortgage loans	0	0
Investment funds	0	0
Policy loans	0	0
Funds withheld at interest	0	0
Other investments	0	0
Short-term investments		0
Total assets measured at fair value	0	0
Liabilities
Interest sensitive contract liabilities	0	0
Long-term debt	0	0
Securities Sold under Agreements to Repurchase	0	0
Funds withheld liability	0	0
Total liabilities not carried at fair value	0	0
Short-term Debt		0
Level 3 | Fair Value
Assets
Mortgage loans	15,636	14,719
Investment funds	0	0
Policy loans	0	0
Funds withheld at interest	41,506	14,380
Other investments	256	65
Short-term investments		190
Total assets measured at fair value	70,902	43,158
Liabilities
Interest sensitive contract liabilities	90,369	58,027
Long-term debt	0	0
Securities Sold under Agreements to Repurchase	0	0
Funds withheld liability	0	0
Total liabilities not carried at fair value	90,369	58,027
Short-term Debt		0
NAV | Fair Value
Assets
Investment funds	536	596
Total assets measured at fair value	3,928	3,327
Level 2 | Fair Value
Assets
Mortgage loans	0	0
Investment funds	0	0
Policy loans	393	417
Funds withheld at interest	0	0
Other investments	0	0
Short-term investments		0
Total assets measured at fair value	393	417
Liabilities
Interest sensitive contract liabilities	0	0
Long-term debt	1,035	1,036
Securities Sold under Agreements to Repurchase	1,599	512
Funds withheld liability	381	377
Total liabilities not carried at fair value	3,015	2,400
Short-term Debt		475
Related Party
Assets
Mortgage loans	626	653
Investment funds	5,278	3,550
Funds withheld at interest	12,971	13,220
Other investments	474	487
Liabilities
Interest sensitive contract liabilities	14,609	15,285
Funds withheld liability	0	0
Related Party | Carrying Value
Assets
Mortgage loans	626	653
Investment funds	3,393	2,731
Funds withheld at interest	12,411	12,626
Other investments	474	487
Related Party | Fair Value
Assets
Mortgage loans	617	641
Investment funds	3,392	2,731
Funds withheld at interest	12,411	12,626
Other investments	476	537
Related Party | Level 1 | Fair Value
Assets
Mortgage loans	0	0
Investment funds	0	0
Funds withheld at interest	0	0
Other investments	0	0
Related Party | Level 3 | Fair Value
Assets
Mortgage loans	617	641
Investment funds	0	0
Funds withheld at interest	12,411	12,626
Other investments	476	537
Related Party | NAV | Fair Value
Assets
Investment funds	3,392	2,731
Related Party | Level 2 | Fair Value
Assets
Mortgage loans	0	0
Investment funds	0	0
Funds withheld at interest	0	0
Other investments	$ 0	$ 0