Investments (Tables)

6 Months Ended

Jun. 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 June 30, 2016	Cost		Gains		Losses		Value
U.S. Treasury securities and obligations of U.S. Government	$	71,863	$	294	$	-	$	72,157
Corporate bonds		178,306		1,680		(465)		179,521
Collateralized corporate bank loans		81,249		356		(493)		81,112
Municipal bonds		180,148		2,572		(2,964)		179,756
Mortgage-backed		56,423		439		(137)		56,725
Total debt securities		567,989		5,341		(4,059)		569,271
Total equity securities		30,249		20,327		(1,116)		49,460
Total debt and equity securities	$	598,238	$	25,668	$	(5,175)	$	618,731
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 June 30,				Six Months Ended June 30,
	2016		2015		2016		2015
U.S. Treasury securities and  obligations of U.S. Government	$	-	$	-	$	-	$	-
Corporate bonds		-		-		80		-
Collateralized corporate bank loans		(36)		132		(18)		150
Municipal bonds		(44)		(16)		(68)		(42)
Mortgage-backed		-		53		-		240
Equity securities		490		4,823		490		5,505
Gain on investments		410		4,992		484		5,853
Other-than-temporary impairments		(2,587)		(1,553)		(2,888)		(1,830)
Net realized gains	$	(2,177)	$	3,439	$	(2,404)	$	4,023

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 June 30, 2016 and December 31, 2015 (in thousands):

	As of June 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		44,961		(465)		-		-		44,961		(465)
Collateralized corporate bank loans		37,748		(430)		4,316		(63)		42,064		(493)
Municipal bonds		14,803		(325)		17,860		(2,639)		32,663		(2,964)
Mortgage-backed		34,437		(135)		41		(2)		34,478		(137)
Total debt securities		131,949		(1,355)		22,217		(2,704)		154,166		(4,059)
Total equity securities		4,341		(435)		1,689		(681)		6,030		(1,116)
Total debt and equity securities	$	136,290	$	(1,790)	$	23,906	$	(3,385)	$	160,196	$	(5,175)
	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	$	82,681	$	82,667
Due after one year through five years		272,930		274,259
Due after five years through ten years		99,094		98,222
Due after ten years		56,861		57,398
Mortgage-backed		56,423		56,725
	$	567,989	$	569,271