Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 segments	Sep. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Number of business segments			2
Net premiums earned	$ 176,531	$ 158,704	$ 508,124	$ 425,118
Investment income, net of investment expenses	28,665	26,926	86,560	81,730
Net realized investment gains	1,300	1,219	4,658	4,996
Other income	85	725	584	1,610
Total Revenue	206,581	187,574	599,926	513,454
Net income (loss)	8,730	(4,776)	42,630	(16,880)
Assets	3,737,810		3,737,810		3,618,924
Invested assets	3,069,066		3,069,066		2,908,008
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net premiums earned	176,644	158,796	508,459	425,394
Investment income, net of investment expenses	28,707	26,872	86,684	81,827
Net realized investment gains	1,300	1,219	4,658	4,996
Other income	85	725	584	1,610
Total reportable segment	206,736	187,612	600,385	513,827
Intersegment eliminations	(155)	(38)	(459)	(373)
Total Revenue	206,581	187,574	599,926	513,454
Net income (loss)	8,730	(4,776)	42,630	(16,880)
Assets	3,737,810	3,604,745	3,737,810	3,604,745
Invested assets	3,069,066	2,867,422	3,069,066	2,867,422
Property and Casualty Insurance [Member]
Segment Reporting Information [Line Items]
Number of business locations	6		6
Net premiums earned	161,232	144,065	461,902	384,838
Investment income, net of investment expenses	11,093	8,129	33,533	26,405
Net realized investment gains	1,214	692	1,765	2,293
Other income	(19)	504	177	1,042
Total reportable segment	173,520	153,390	497,377	414,578
Intersegment eliminations	(42)	(44)	(124)	(132)
Total Revenue	173,478	153,346	497,253	414,446
Net income (loss)	7,616	(6,671)	37,607	(22,895)
Assets	1,923,407	1,878,705	1,923,407	1,878,705
Invested assets	1,334,278	1,265,170	1,334,278	1,265,170
Life Insurance [Member]
Segment Reporting Information [Line Items]
Net premiums earned	15,412	14,731	46,557	40,556
Investment income, net of investment expenses	17,614	18,743	53,151	55,422
Net realized investment gains	86	527	2,893	2,703
Other income	104	221	407	568
Total reportable segment	33,216	34,222	103,008	99,249
Intersegment eliminations	(113)	6	(335)	(241)
Total Revenue	33,103	34,228	102,673	99,008
Net income (loss)	1,114	1,895	5,023	6,015
Assets	1,814,403	1,726,040	1,814,403	1,726,040
Invested assets	$ 1,734,788	$ 1,602,252	$ 1,734,788	$ 1,602,252