Variable Interest Entities (Assets and Liabilities of Consolidated VIEs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Assets	$ 940,722	$ 896,552
Total liabilities	872,512	832,833
Consolidated VIEs for Which the Company is the Investment Manager
Variable Interest Entity [Line Items]
Assets	4,292	5,048
Total liabilities	561	1,578
Consolidated VIEs for Which the Company is the Investment Manager | Wholly-owned Beneficial Interests
Variable Interest Entity [Line Items]
Assets	2,538	2,668
Consolidated VIEs for Which the Company is the Investment Manager | Assets supporting experience-rated contractholder liabilities
Variable Interest Entity [Line Items]
Assets	0	0
Consolidated VIEs for Which the Company is the Investment Manager | Equity securities
Variable Interest Entity [Line Items]
Assets	42	47
Consolidated VIEs for Which the Company is the Investment Manager | Commercial mortgage and other loans
Variable Interest Entity [Line Items]
Assets	975	883
Consolidated VIEs for Which the Company is the Investment Manager | Other
Variable Interest Entity [Line Items]
Assets	2,221	2,199
Consolidated VIEs for Which the Company is the Investment Manager | Cash and cash equivalents
Variable Interest Entity [Line Items]
Assets	101	166
Consolidated VIEs for Which the Company is the Investment Manager | Accrued investment income
Variable Interest Entity [Line Items]
Assets	2	4
Consolidated VIEs for Which the Company is the Investment Manager | Other assets
Variable Interest Entity [Line Items]
Assets	594	450
Consolidated VIEs for Which the Company is the Investment Manager | Other liabilities
Variable Interest Entity [Line Items]
Total liabilities	256	304
Consolidated VIEs for Which the Company is the Investment Manager | Notes issued by consolidated VIEs
Variable Interest Entity [Line Items]
Total liabilities	305	1,274
Other Consolidated VIEs
Variable Interest Entity [Line Items]
Assets	2,077	1,910
Total liabilities	2	13
Other Consolidated VIEs | Assets supporting experience-rated contractholder liabilities
Variable Interest Entity [Line Items]
Assets	0	4
Other Consolidated VIEs | Equity securities
Variable Interest Entity [Line Items]
Assets	0	0
Other Consolidated VIEs | Commercial mortgage and other loans
Variable Interest Entity [Line Items]
Assets	0	0
Other Consolidated VIEs | Other
Variable Interest Entity [Line Items]
Assets	127	89
Other Consolidated VIEs | Cash and cash equivalents
Variable Interest Entity [Line Items]
Assets	0	0
Other Consolidated VIEs | Accrued investment income
Variable Interest Entity [Line Items]
Assets	4	4
Other Consolidated VIEs | Other assets
Variable Interest Entity [Line Items]
Assets	768	689
Other Consolidated VIEs | Other liabilities
Variable Interest Entity [Line Items]
Total liabilities	2	13
Other Consolidated VIEs | Notes issued by consolidated VIEs
Variable Interest Entity [Line Items]
Total liabilities	0	0
Available-for-sale | Consolidated VIEs for Which the Company is the Investment Manager | Fixed maturities
Variable Interest Entity [Line Items]
Assets	110	104
Available-for-sale | Other Consolidated VIEs | Fixed maturities
Variable Interest Entity [Line Items]
Assets	296	285
Held-to-maturity | Consolidated VIEs for Which the Company is the Investment Manager | Fixed maturities
Variable Interest Entity [Line Items]
Assets	87	83
Held-to-maturity | Other Consolidated VIEs | Fixed maturities
Variable Interest Entity [Line Items]
Assets	882	839
Trading | Consolidated VIEs for Which the Company is the Investment Manager | Fixed maturities
Variable Interest Entity [Line Items]
Assets	160	1,112
Trading | Other Consolidated VIEs | Fixed maturities
Variable Interest Entity [Line Items]
Assets	$ 0	$ 0
Maximum | Consolidated VIEs for Which the Company is the Investment Manager | Notes issued by consolidated VIEs
Variable Interest Entity [Line Items]
Debt Instrument, Term	4 years