Investments - Investments - Fixed Maturities, AFS, by Contractual Maturity Year (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Amortized Cost
One year or less	$ 1,593	$ 1,082
Over one year through five years	6,872	7,200
Over five years through ten years	8,166	7,395
Over ten years	11,934	11,769
Subtotal	28,565	27,446
Mortgage-backed and asset-backed securities	12,508	12,632
Fixed maturities, available-for-sale, at fair value, amortized cost	41,073	40,078
Fair Value
One year or less	1,614	1,090
Over one year through five years	7,229	7,401
Over five years through ten years	8,769	7,803
Over ten years	13,501	12,988
Subtotal	31,113	29,282
Mortgage-backed and asset-backed securities	12,931	12,866
Fixed maturities, available-for-sale, at fair value (amortized cost of $54,478 and $53,805)	$ 44,044	$ 42,148