Investments (Tables)

6 Months Ended

Jun. 30, 2018

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, 2018	Cost		Gains		Losses		Value
U.S. Treasury securities and obligations of U.S. Government	$	47,852	$	-	$	(719)	$	47,133
Corporate bonds		250,817		366		(1,899)		249,284
Collateralized corporate bank loans		130,377		337		(470)		130,244
Municipal bonds		124,396		6,127		(926)		129,597
Mortgage-backed		13,078		18		(528)		12,568
Total debt securities		566,520		6,848		(4,542)		568,826
Total equity securities		40,308		21,446		(3,840)		57,914
Total other investments		3,763		-		(703)		3,060
Total investments	$	610,591	$	28,294	$	(9,085)	$	629,800
As of December 31, 2017
U.S. Treasury securities and obligations of U.S. Government	$	50,088	$	7	$	(148)	$	49,947
Corporate bonds		278,611		1,204		(742)		279,073
Collateralized corporate bank loans		125,536		702		(301)		125,937
Municipal bonds		134,052		709		(505)		134,256
Mortgage-backed		16,712		37		(216)		16,533
Total debt securities		604,999		2,659		(1,912)		605,746
Total equity securities		30,253		23,014		(1,504)		51,763
Total other investments		3,763		61		-		3,824
Total investments	$	639,015	$	25,734	$	(3,416)	$	661,333

Summary of Realized Gain (Loss) on Investments

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

	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
U.S. Treasury securities and obligations of U.S. Government	$	-	$	-	$	-	$	-
Corporate bonds		(14)		(148)		(22)		(18)
Collateralized corporate bank loans		35		20		47		48
Municipal bonds		2		101		(19)		84
Mortgage-backed		(1)		-		1		-
Realized gains (losses) on fixed maturities		22		(27)		7		114
Realized gains (losses) on equity securities		359		17		359		2,377
Realized gains (losses) on other investments		-		-		-		-
Total realized gains (losses) on investments		381		(10)		366		2,491
Other-than-temporary impairments		-		(3,407)		-		(3,407)
Unrealized losses on other investments		(401)		(62)		(764)		(503)
Unrealized gains (losses) on equity investments		553		-		(3,904)		-
Investment gains (losses), net	$	533	$	(3,479)	$	(4,302)	$	(1,419)

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, 2018 and December 31, 2017 (in thousands):

	As of June 30, 2018
	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	$	47,133	$	(719)	$	-	$	-	$	47,133	$	(719)
Corporate bonds		227,333		(1,898)		379		(1)		227,712		(1,899)
Collateralized corporate bank loans		77,457		(379)		5,687		(91)		83,144		(470)
Municipal bonds		35,600		(783)		7,980		(143)		43,580		(926)
Mortgage-backed		7,728		(324)		926		(204)		8,654		(528)
Total debt securities		395,251		(4,103)		14,972		(439)		410,223		(4,542)
Total equity securities		13,106		(2,990)		2,564		(850)		15,670		(3,840)
Total other investments		3,060		(703)		-		-		3,060		(703)
Total investments	$	411,417	$	(7,796)	$	17,536	$	(1,289)	$	428,953	$	(9,085)
	As of December 31, 2017
	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	$	28,825	$	(145)	$	1,997	$	(3)	$	30,822	$	(148)
Corporate bonds		176,061		(736)		2,378		(6)		178,439		(742)
Collateralized corporate bank loans		30,008		(280)		2,517		(21)		32,525		(301)
Municipal bonds		35,200		(370)		8,917		(135)		44,117		(505)
Mortgage-backed		6,419		(127)		1,415		(89)		7,834		(216)
Total debt securities		276,513		(1,658)		17,224		(254)		293,737		(1,912)
Total equity securities		8,375		(1,504)		-		-		8,375		(1,504)
Total other investments		-		-		-		-		-		-
Total investments	$	284,888	$	(3,162)	$	17,224	$	(254)	$	302,112	$	(3,416)

Carrying Value of Other Invested Assets Portfolio

Details regarding the carrying value of the other investments portfolio as of June 30, 2018 and December 31, 2017 are as follows (in thousands):

	June 30,		December 31,
	2018		2017
Investment Type
Equity warrant	$	3,060	$	3,824
Total other investments	$	3,060	$	3,824

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	$	134,743	$	134,885
Due after one year through five years		265,203		268,821
Due after five years through ten years		125,657		125,402
Due after ten years		27,839		27,150
Mortgage-backed		13,078		12,568
	$	566,520	$	568,826