Consolidated Statements of Income and Comprehensive Income (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Revenues
Net premiums earned	$ 754,846	$ 694,994		$ 586,783
Investment income, net of investment expenses	112,799	111,905		109,494
Net realized investment gains (losses)
Other-than-temporary impairment charges	(139)	(4)		(395)
All other net realized gains (includes reclassifications for net unrealized gains on available-for-sale securities of $6,812 in 2013; $4,102 in 2012; and $7,369 in 2011 previously included in accumulated other comprehensive income)	8,834	5,457		6,835
Total net realized investment gains	8,695	5,453		6,440
Other income	702	891		2,291
Total revenues	877,042	813,243		705,008
Benefits, Losses and Expenses
Losses and loss settlement expenses	458,814	459,706		430,389
Increase in liability for future policy benefits	37,625	43,095		32,567
Amortization of deferred policy acquisition costs	153,677	141,834		153,176
Other underwriting expenses (includes reclassifications for employee benefit costs of $5,868 in 2013; $4,971 in 2012; and $2,570 in 2011 previously included in accumulated other comprehensive income)	89,861	81,125		58,757
Interest on policyholders’ accounts	35,163	41,409		42,834
Total benefits, losses and expenses	775,140	767,169		717,723
Income (loss) before income taxes	101,902	46,074		(12,715)
Federal income tax expense (benefit) (includes reclassifications of ($331) in 2013; $304 in 2012; and ($1,680) in 2011 previously included in accumulated other comprehensive income)	25,762	5,862		(12,726)
Net income	76,140	40,212		11
Other comprehensive income (loss)
Change in net unrealized appreciation on investments	(35,489)	34,436		40,795
Change in liability for underfunded employee benefit plans	24,066	(15,922)		(27,528)
Other comprehensive income (loss), before tax and reclassification adjustments	(11,423)	18,514		13,267
Income tax effect	3,998	(6,477)		(4,540)
Other comprehensive income (loss), after tax, before reclassification adjustments	(7,425)	12,037		8,727
Reclassifications for unrealized net gains on available-for-sale securities	(6,812)	(4,102)		(7,369)
Reclassification adjustment for employee benefit costs included in expense	5,868	4,971		2,570
Total reclassification adjustments, before tax	(944)	869		(4,799)
Income tax effect	331	(304)		1,680
Total reclassification adjustments, after tax	(613)	565		(3,119)
Comprehensive income	$ 68,102	$ 52,814		$ 5,619
Weighted average common shares outstanding (in shares)	25,325,695	25,447,918		25,878,535
Basic earnings per common share (in usd per share)	$ 3.01	$ 1.58	[1]	$ 0.00
Diluted earnings per common share (in usd per share)	$ 2.98	$ 1.58	[1]	$ 0.00

[1] The sum of the quarterly reported amounts may not equal the full year, as each is computed independently.