Variable Interest Entities (Assets and Liabilities of Consolidated VIEs) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Total liabilities of consolidated VIEs	[1]	$ 1,274	$ 955
Consolidated VIEs for Which the Company is the Investment Manager
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		5,048	4,140
Total liabilities of consolidated VIEs		1,578	1,250
Consolidated VIEs for Which the Company is the Investment Manager | Assets supporting experience-rated contractholder liabilities
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		0	0
Consolidated VIEs for Which the Company is the Investment Manager | Equity securities
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		47	41
Consolidated VIEs for Which the Company is the Investment Manager | Commercial mortgage and other loans
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		883	730
Consolidated VIEs for Which the Company is the Investment Manager | Other
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		2,199	1,526
Consolidated VIEs for Which the Company is the Investment Manager | Cash and cash equivalents
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		166	131
Consolidated VIEs for Which the Company is the Investment Manager | Accrued investment income
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		4	5
Consolidated VIEs for Which the Company is the Investment Manager | Other assets
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		450	463
Consolidated VIEs for Which the Company is the Investment Manager | Other liabilities
Variable Interest Entity [Line Items]
Total liabilities of consolidated VIEs		304	295
Consolidated VIEs for Which the Company is the Investment Manager | Notes issued by consolidated VIEs
Variable Interest Entity [Line Items]
Total liabilities of consolidated VIEs		1,274	955
Other Consolidated VIEs
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		1,910	1,923
Total liabilities of consolidated VIEs		13	17
Other Consolidated VIEs | Assets supporting experience-rated contractholder liabilities
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		4	8
Other Consolidated VIEs | Equity securities
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		0	0
Other Consolidated VIEs | Commercial mortgage and other loans
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		0	0
Other Consolidated VIEs | Other
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		89	77
Other Consolidated VIEs | Cash and cash equivalents
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		0	0
Other Consolidated VIEs | Accrued investment income
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		4	4
Other Consolidated VIEs | Other assets
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		689	721
Other Consolidated VIEs | Other liabilities
Variable Interest Entity [Line Items]
Total liabilities of consolidated VIEs		13	17
Other Consolidated VIEs | Notes issued by consolidated VIEs
Variable Interest Entity [Line Items]
Total liabilities of consolidated VIEs		0	0
Available-for-sale | Consolidated VIEs for Which the Company is the Investment Manager | Fixed maturities
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		104	73
Available-for-sale | Other Consolidated VIEs | Fixed maturities
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		285	282
Held-to-maturity | Consolidated VIEs for Which the Company is the Investment Manager | Fixed maturities
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		83	95
Held-to-maturity | Other Consolidated VIEs | Fixed maturities
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		839	831
Trading | Consolidated VIEs for Which the Company is the Investment Manager | Fixed maturities
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		1,112	1,076
Trading | Other Consolidated VIEs | Fixed maturities
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		0	0
ASU 2015-02, Wholly-owned by consolidated subsidiaries | Consolidated VIEs for Which the Company is the Investment Manager
Variable Interest Entity [Line Items]
Total assets of consolidated VIEs		$ 2,668	$ 2,013
Maximum | Consolidated VIEs for Which the Company is the Investment Manager | Notes issued by consolidated VIEs
Variable Interest Entity [Line Items]
Debt Instrument, Term		9 years
Minimum | 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

[1] See Note 4 for details of balances associated with variable interest entities.