Federal Income Taxes (Deferred Tax Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets:
Future policy benefits, excess of financial accounting liabilities over tax liabilities	$ 292,262	$ 305,795
Investment securities write-downs for financial accounting purposes	6,246	7,523
Pension liabilities	11,333	9,055
Accrued operating expenses recorded for financial accounting purposes not currently tax deductible	5,588	6,778
Foreign currency translation adjustments	4,318	4,355
Accrued and unearned investment income recognized for tax purposes and deferred for financial accounting purposes	390	369
Other	6	6
Total gross deferred tax assets	320,143	333,881
Deferred tax liabilities:
Deferred policy acquisition and sales inducement costs, principally expensed for tax purposes	(311,680)	(305,700)
Debt securities, principally due to deferred market discount for tax	(8,477)	(8,017)
Real estate, principally due to adjustments for financial accounting purposes	(1,023)	(949)
Net unrealized gains on securities available for sale	(25,185)	(21,150)
Fixed assets, due to different bases	(757)	(897)
Other	(4,696)	(4,367)
Total gross deferred tax liabilities	(351,818)	(341,080)
Net deferred tax liabilities	$ (31,675)	$ (7,199)