Investments - Investments - Fixed Maturities, AFS, by Contractual Maturity Year (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Amortized Cost
One year or less	$ 1,394	$ 1,411
Over one year through five years	7,706	7,832
Over five years through ten years	7,755	7,622
Over ten years	12,114	12,206
Subtotal	28,969	29,071
Mortgage-backed and asset-backed securities	12,348	12,490
Fixed maturities, available-for-sale, at fair value, amortized cost	41,317	41,561
Fair Value
One year or less	1,411	1,432
Over one year through five years	8,108	8,286
Over five years through ten years	8,158	8,354
Over ten years	13,254	14,028
Subtotal	30,931	32,100
Mortgage-backed and asset-backed securities	12,676	12,935
Fixed maturities, available-for-sale, at fair value (amortized cost of $54,478 and $53,805)	$ 43,607	$ 45,035