Income Taxes Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets, Gross
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Policyholder Liabilities	$ 1,322	$ 1,483
Deferred Tax Assets, Operating Loss Carryforwards	151	221
Deferred Tax Assets, Tax Credit Carryforwards	6	18
Deferred Tax Assets, Value of Business Acquired	78	69
Deferred Tax Assets, Property, Plant and Equipment	26	0
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation	36	52
Deferred Tax Assets, Other	10	27
Deferred Tax Assets, Gross	1,629	1,870
Deferred Tax Assets, Valuation Allowance	(64)	(72)
Deferred Tax Assets, Net of Valuation Allowance	1,565	1,798
Deferred Tax Liabilities, Gross [Abstract]
Deferred Tax Liabilities, Investments	781	668
Deferred Tax Liabilities, Other Comprehensive Income	317	178
Deferred Tax Liabilities, Value of Business Acquired	328	346
Deferred Tax Liabilities, Deferred Expense, Deferred Policy Acquisition Cost	174	232
Deferred Tax Liabilities, Other	3	6
Deferred Tax Liabilities, Gross	1,603	1,430
Deferred Tax Liabilities, Net	$ 38
Deferred Tax Assets, Net		$ 368