Investments (Tables)

9 Months Ended

Sep. 30, 2016

Investments [Abstract]

Amortized Cost and Estimated Fair Value of Investments in Debt and Equity Securities by Category

The amortized cost and estimated fair value of investments in debt and equity securities by category is as follows (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
As of September 30, 2016	Cost		Gains		Losses		Value
U.S. Treasury securities and obligations of U.S. Government	$	71,891	$	181	$	-	$	72,072
Corporate bonds		205,482		2,412		(193)		207,701
Collateralized corporate bank loans		86,115		447		(127)		86,435
Municipal bonds		169,553		2,006		(2,079)		169,480
Mortgage-backed		64,849		312		(58)		65,103
Total debt securities		597,890		5,358		(2,457)		600,791
Total equity securities		30,309		19,474		(947)		48,836
Total debt and equity securities	$	628,199	$	24,832	$	(3,404)	$	649,627
As of December 31, 2015
U.S. Treasury securities and obligations of U.S. Government	$	76,323	$	7	$	(61)	$	76,269
Corporate bonds		122,894		637		(1,822)		121,709
Collateralized corporate bank loans		83,434		44		(1,882)		81,596
Municipal bonds		196,446		1,888		(5,966)		192,368
Mortgage-backed		59,532		155		(304)		59,383
Total debt securities		538,629		2,731		(10,035)		531,325
Total equity securities		24,951		23,391		(838)		47,504
Total debt and equity securities	$	563,580	$	26,122	$	(10,873)	$	578,829

Summary of Realized Gain (Loss) on Investments

Major categories of net realized gains (losses) on investments are summarized as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
U.S. Treasury securities and  obligations of U.S. Government	$	-	$	-	$	-	$	-
Corporate bonds		(81)		-		(1)		-
Collateralized corporate bank loans		(98)		8		(116)		158
Municipal bonds		(97)		(12)		(165)		(54)
Mortgage-backed		(1)		-		(1)		240
Equity securities		1,382		32		1,872		5,537
Gain on investments		1,105		28		1,589		5,881
Other-than-temporary impairments		-		(363)		(2,888)		(2,193)
Net realized gains (losses)	$	1,105	$	(335)	$	(1,299)	$	3,688

Summary of Gross Unrealized Losses for Investments that have been Continuously in Unrealized Loss Position

The following schedules summarize the gross unrealized losses showing the length of time that investments have been continuously in an unrealized loss position as of September 30, 2016 and December 31, 2015 (in thousands):

	As of September 30, 2016
	12 months or less				Longer than 12 months				Total
			Unrealized				Unrealized				Unrealized
	Fair Value		Losses		Fair Value		Losses		Fair Value		Losses
U.S. Treasury securities and obligations of U.S. Government	$	-	$	-	$	-	$	-	$	-	$	-
Corporate bonds		42,945		(164)		2,694		(29)		45,639		(193)
Collateralized corporate bank loans		10,252		(69)		11,381		(58)		21,633		(127)
Municipal bonds		16,102		(282)		16,897		(1,797)		32,999		(2,079)
Mortgage-backed		17,794		(42)		10,821		(16)		28,615		(58)
Total debt securities		87,093		(557)		41,793		(1,900)		128,886		(2,457)
Total equity securities		6,569		(364)		1,761		(583)		8,330		(947)
Total debt and equity securities	$	93,662	$	(921)	$	43,554	$	(2,483)	$	137,216	$	(3,404)
	As of December 31, 2015
	12 months or less				Longer than 12 months				Total
			Unrealized				Unrealized				Unrealized
	Fair Value		Losses		Fair Value		Losses		Fair Value		Losses
U.S. Treasury securities and obligations of U.S. Government	$	41,428	$	(61)	$	-	$	-	$	41,428	$	(61)
Corporate bonds		96,475		(1,822)		-		-		96,475		(1,822)
Collateralized corporate bank loans		65,868		(1,758)		3,532		(124)		69,400		(1,882)
Municipal bonds		44,525		(488)		25,310		(5,478)		69,835		(5,966)
Mortgage-backed		36,251		(302)		48		(2)		36,299		(304)
Total debt securities		284,547		(4,431)		28,890		(5,604)		313,437		(10,035)
Total equity securities		6,584		(838)		-		-		6,584		(838)
Total debt and equity securities	$	291,131	$	(5,269)	$	28,890	$	(5,604)	$	320,021	$	(10,873)

Schedule of Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturities

	Amortized		Fair
	Cost		Value
	(in thousands)
Due in one year or less	$	81,699	$	81,687
Due after one year through five years		297,438		298,846
Due after five years through ten years		97,531		98,574
Due after ten years		56,373		56,581
Mortgage-backed		64,849		65,103
	$	597,890	$	600,791