Investments (Variable Interest Entities) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Carrying amount	$ 214,306	$ 216,153
VIE, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Carrying amount	14,544	14,851
Maximum exposure to loss	15,314	15,382
VIE, Not Primary Beneficiary | Fixed maturity securities
Variable Interest Entity [Line Items]
Carrying amount	12,537	12,959
Maximum exposure to loss	12,092	12,317
VIE, Not Primary Beneficiary | Limited partnerships and LLCs
Variable Interest Entity [Line Items]
Carrying amount	2,007	1,892
Maximum exposure to loss	$ 3,222	$ 3,065