Investments (Unconsolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Assets	$ 795,146	$ 740,463
Tax Credits Guaranteed By Third Parties Amount That Reduces Maximum Exposure To Loss Related To Other Invested Assets	3	6
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	70,409	62,481
Maximum Exposure to Loss	77,069	67,996
Variable Interest Entity, Not Primary Beneficiary | Structured Products
Variable Interest Entity [Line Items]
Assets	56,962	51,962
Maximum Exposure to Loss	56,962	51,962
Variable Interest Entity, Not Primary Beneficiary | U.S. corporate and foreign corporate
Variable Interest Entity [Line Items]
Assets	3,011	1,764
Maximum Exposure to Loss	3,011	1,764
Variable Interest Entity, Not Primary Beneficiary | Foreign government
Variable Interest Entity [Line Items]
Assets	142	136
Maximum Exposure to Loss	142	136
Variable Interest Entity, Not Primary Beneficiary | Other limited partnership interests
Variable Interest Entity [Line Items]
Assets	8,355	6,674
Maximum Exposure to Loss	14,911	12,016
Variable Interest Entity, Not Primary Beneficiary | Other invested assets
Variable Interest Entity [Line Items]
Assets	1,320	1,495
Maximum Exposure to Loss	1,404	1,621
Variable Interest Entity, Not Primary Beneficiary | Other Investments
Variable Interest Entity [Line Items]
Assets	619	450
Maximum Exposure to Loss	$ 639	$ 497