Income Taxes (Deferred Income Tax Assets and Liabilities) (Details 3) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Deferred income tax assets:
Liabilities for policyholder account balances, future policy benefits and claims	$ 1,177	$ 1,391
Deferred compensation	439	384
Investment related	253	118
Postretirement benefits	62	56
Loss carryovers and tax credit carryforwards	73
Other	68	87
Gross deferred income tax assets	2,072	2,036
Less: Valuation allowance	11	11
Total deferred income tax assets	2,061	2,025
Deferred income tax liabilities:
Deferred acquisition costs	717	730
Net unrealized gains on Available-for-Sale securities	264	233
Depreciation expense	146	169
Deferred sales inducement costs	113	125
Intangible assets	126	113
Goodwill	74	66
Other	2	18
Gross deferred income tax liabilities	1,442	1,454
Net deferred income tax liabilities	619	571
State net operating losses	14
Valuation allowance	$ 11	$ 11