Investments (Unconsolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Total Assets	$ 769,814	$ 795,146
Tax Credits Guaranteed By Third Parties Amount That Reduces Maximum Exposure To Loss Related To Other Invested Assets	3	3
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Total Assets	70,136	70,409
Maximum Exposure to Loss	76,581	77,069
Variable Interest Entity, Not Primary Beneficiary | Fixed Maturity Securities
Variable Interest Entity [Line Items]
Total Assets	58,442	60,115
Maximum Exposure to Loss	58,442	60,115
Variable Interest Entity, Not Primary Beneficiary | Other limited partnership interests
Variable Interest Entity [Line Items]
Total Assets	9,771	8,355
Maximum Exposure to Loss	16,133	14,911
Variable Interest Entity, Not Primary Beneficiary | Other invested assets
Variable Interest Entity [Line Items]
Total Assets	1,289	1,320
Maximum Exposure to Loss	1,369	1,404
Variable Interest Entity, Not Primary Beneficiary | Other Investments
Variable Interest Entity [Line Items]
Total Assets	634	619
Maximum Exposure to Loss	$ 637	$ 639