Investments (Tables)

3 Months Ended

Mar. 31, 2013

Summary of Investment Holdings [Line Items]

Gross unrealized gains and losses and the cost and fair value of investments classified as held-to-maturity

	Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
States and political subdivisions	$	399,453	$	29,472	$	(193	)	$	428,732
Corporate bonds		77,596		1,429		(20	)		79,005
Commercial mortgage-backed securities		51,524		5,453		—			56,977
U.S. agency-based mortgage-backed securities		30,077		2,809		—			32,886
U.S. Treasury securities and obligations of U.S. Government agencies		11,027		1,597		—			12,624
Asset-backed securities		4,011		224		(111	)		4,124
Totals	$	573,688	$	40,984	$	(324	)	$	614,348

	Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
States and political subdivisions	$	400,687	$	31,387	$	(106	)	$	431,968
Corporate bonds		82,824		1,565		(12	)		84,377
Commercial mortgage-backed securities		51,529		6,433		—			57,962
U.S. agency-based mortgage-backed securities		32,984		3,063		(5	)		36,042
U.S. Treasury securities and obligations of U.S. Government agencies		11,034		1,721		—			12,755
Asset-backed securities		4,229		192		(176	)		4,245
Totals	$	583,287	$	44,361	$	(299	)	$	627,349

Gross unrealized gains and losses and the cost and fair value of investments classified as available-for-sale

	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
Fixed Maturity:
States and political subdivision	$	113,232	$	4,579	$	(444	)	$	117,367
Corporate bonds		52,055		636		(12	)		52,679
U.S. agency-based mortgage-backed securities		11,089		23		(1,046	)		10,066
Total Fixed Maturity		176,376		5,238		(1,502	)		180,112
Equity securities		15,336		761		(900	)		15,197
Totals	$	191,712	$	5,999	$	(2,402	)	$	195,309

	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
Fixed Maturity:
States and political subdivision	$	93,362	$	5,022	$	(142	)	$	98,242
Corporate bonds		39,211		623		(24	)		39,810
U.S. agency-based mortgage-backed securities		11,941		5		(859	)		11,087
Total Fixed Maturity		144,514		5,650		(1,025	)		149,139
Equity securities		7,000		451		(685	)		6,766
Totals	$	151,514	$	6,101	$	(1,710	)	$	155,905

Investment securities continuous unrealized loss position

	As of March 31, 2013
	Less Than 12 Months				12 Months or Greater				Total
	Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses		Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses		Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses
	(in thousands)
Held-to-Maturity
Fixed maturity securities:
Corporate bonds	$	20,763	$	20	$	—	$	—	$	20,763	$	20
States and political subdivisions		16,824		193		—		—		16,824		193
Asset-backed securities		—		—		2,243		111		2,243		111
Total held-to-maturity securities		37,587		213		2,253		111		39,840		324
Available-for Sale
Fixed maturity securities:
Corporate bonds	$	11,381	$	12	$	—	$	—	$	11,381	$	12
States and political subdivisions		31,529		444		—		—		31,529		444
U.S. agency-based mortgage-backed securities		8,731		1,046		—		—		8,731		1,046
Equity Securities		4,942		440		1,492		460		6,434		900
Total available-for-sale securities		56,583		1,942		1,492		460		58,075		2,402
Total	$	94,170	$	2,155	$	3,745	$	571	$	97,915	$	2,726

	As of December 31, 2012
	Less Than 12 Months				12 Months or Greater				Total
	Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses		Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses		Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses
	(in thousands)
Held-to-Maturity
Fixed maturity securities:
Corporate bonds	$	10,734	$	12	$	—	$	—	$	10,734	$	12
State and political subdivisions		11,913		106		—		—		11,913		106
U.S. agency-based mortgage-backed securities		117		—		68		5		185		5
Asset-backed securities		—		—		2,277		176		2,277		176
Total held-to-maturity securities		22,764		118		2,345		181		25,109		299
Available-for Sale
Fixed maturity securities:
Corporate bonds	$	6,411	$	24	$	—	$	—	$	6,411	$	24
States and political subdivisions		6,281		142		—		—		6,281		142
U.S. agency-based mortgage-backed securities		10,919		859		—		—		10,919		859
Equity Securities		4,186		685		—		—		4,186		685
Total available-for-sale securities		27,797		1,710		—		—		27,797		1,710
Total	$	50,561	$	1,828	$	2,345	$	181	$	52,906	$	2,009

Total held-to-maturity securities [Member]

Summary of Investment Holdings [Line Items]

Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, by contractual maturity

Remaining Time to Maturity	Carrying Value		Fair Value
	(in thousands)
Less than one year	$	67,683	$	68,316
One to five years		151,891		160,322
Five to ten years		134,470		149,054
More than ten years		134,032		142,669
U.S. agency-based mortgage-backed securities		30,077		32,886
Commercial mortgage-backed securities		51,524		56,977
Asset-backed securities		4,011		4,124
Total	$	573,688	$	614,348

Total available-for-sale securities [Member]

Summary of Investment Holdings [Line Items]

Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, by contractual maturity

Remaining Time to Maturity	Carrying Value		Fair Value
	(in thousands)
Less than one year	$	15,019	$	15,066
One to five years		29,431		29,791
Five to ten years		18,914		19,608
More than ten years		101,923		105,581
U.S. agency-based mortgage-backed securities		11,089		10,066
Total	$	176,376	$	180,112