Federal Income Taxes (Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Reconciliation [Abstract]
Income tax expense at statutory rate of 35%	$ 51,334	$ 55,133	$ 49,594
Dividend received deduction	(1,194)	(1,076)	(1,140)
Tax adjustment on foreign currency	(2,195)	(2,155)	(2,065)
Tax adjustment on foreign currency	618	(358)	(214)
Adjustments pertaining to prior tax years	(296)	1	(273)
Nondeductible insurance	160	160	160
Nondeductible expenses	261	277	121
Other, net	(416)	(49)	(733)
Taxes on earnings from continuing operations	$ 48,272	$ 51,933	$ 45,450
Statutory Rate	35.00%