Nature of Operations and Basis of Presentation (Deferred Policy Acquisition Costs) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Recorded asset at beginning of period	$ 168,264
Underwriting costs deferred	165,763
Amortization of deferred policy acquisition costs	(156,932)
Ending unamortized deferred policy acquisition costs	177,095
Impact of unrealized gains and losses on available-for-sale securities	(19,857)	$ 2,113
Recorded asset at end of period	157,238
Property and Casualty Insurance
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Recorded asset at beginning of period	90,547
Underwriting costs deferred	161,484
Amortization of deferred policy acquisition costs	(151,216)
Ending unamortized deferred policy acquisition costs	100,815
Impact of unrealized gains and losses on available-for-sale securities	0
Recorded asset at end of period	100,815
Life Insurance
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Recorded asset at beginning of period	77,717
Underwriting costs deferred	4,279
Amortization of deferred policy acquisition costs	(5,716)
Ending unamortized deferred policy acquisition costs	76,280
Impact of unrealized gains and losses on available-for-sale securities	(19,857)
Recorded asset at end of period	$ 56,423