Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Components of the deferred income tax assets and liabilities
Unrecognized tax benefits	$ 2,000,000	$ 1,000,000	$ 1,000,000	$ 0
Unrecognized tax benefits, income tax penalties and interest accrued	0	0	$ 0
Unrecognized tax benefits, interest on income taxes accrued	0	0
Tax penalties or interest accrued		$ 0
Tax Cuts And Jobs Act Of 2017, Deferred tax asset, provisional income tax benefit	$ 514,000,000
Statutory federal income tax rate expense	35.00%	35.00%	35.00%
Tax Legislation benefit	71.80%	(0.00%)	(0.00%)
Deferred assets
Deferred reinsurance gain	$ 8,000,000	$ 16,000,000
Other assets	2,000,000	4,000,000
Total deferred assets (1)	10,000,000	20,000,000
Deferred liabilities
Life and annuity reserves	(269,000,000)	(362,000,000)
Unrealized net capital gains	(223,000,000)	(369,000,000)
DAC	(221,000,000)	(370,000,000)
Difference in tax bases of investments	(79,000,000)	(35,000,000)
Other liabilities	(54,000,000)	(75,000,000)
Total deferred liabilities	(846,000,000)	(1,211,000,000)
Net deferred liability	(836,000,000)	(1,191,000,000)
Components of income tax expense
Current	104,000,000	24,000,000	$ 251,000,000
Deferred	(382,000,000)	120,000,000	50,000,000
Total income tax (benefit) expense	(278,000,000)	144,000,000	301,000,000
Income tax refunds received	1,000,000	22,000,000
Income taxes paid			$ 221,000,000
Current income tax receivable	$ 56,000,000	$ 16,000,000
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation
Statutory federal income tax rate - expense	35.00%	35.00%	35.00%
Tax Legislation benefit	71.80%	(0.00%)	(0.00%)
Tax credits	(1.70%)	(3.30%)	(1.70%)
Dividends received deduction	(0.60%)	(1.30%)	(0.60%)
Adjustments to prior year tax liabilities	(0.30%)	(0.00%)	(0.30%)
State income taxes	0.60%	0.30%	0.40%
Non-deductible expenses	0.10%	0.20%	0.20%
Change in accounting for investments in qualified affordable housing projects	0.00%	0.00%	2.00%
Other	0.00%	0.10%	(0.10%)
Effective income tax rate (benefit) expense	38.70%	(31.00%)	(34.90%)