Investments (Tables)

3 Months Ended

Mar. 31, 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 March 31, 2018	Cost		Gains		Losses		Value
U.S. Treasury securities and obligations of U.S. Government	$	49,972	$	-	$	(554)	$	49,418
Corporate bonds		257,521		557		(1,893)		256,185
Collateralized corporate bank loans		137,713		827		(133)		138,407
Municipal bonds		135,256		2,753		(821)		137,188
Mortgage-backed		15,019		28		(399)		14,648
Total debt securities		595,481		4,165		(3,800)		595,846
Total equity securities		35,762		21,238		(4,185)		52,815
Total other investments		3,763		-		(302)		3,461
Total investments	$	635,006	$	25,403	$	(8,287)	$	652,122
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 March 31,
	2018		2017
U.S. Treasury securities and  obligations of U.S. Government	$	-	$	-
Corporate bonds		(8)		130
Collateralized corporate bank loans		12		28
Municipal bonds		(21)		(17)
Mortgage-backed		2		-
Equity securities		-		2,360
Other investments		-		-
Realized (losses) gain on investments		(15)		2,501
Unrealized losses on other investments		(363)		(441)
Unrealized losses on equity investments		(4,457)		-
Investment (losses) gains, net	$	(4,835)	$	2,060

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

	As of March 31, 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	$	47,418	$	(553)	$	1,999	$	(1)	$	49,417	$	(554)
Corporate bonds		218,114		(1,861)		1,385		(32)		219,499		(1,893)
Collateralized corporate bank loans		16,828		(43)		8,006		(90)		24,834		(133)
Municipal bonds		38,925		(607)		10,232		(214)		49,157		(821)
Mortgage-backed		4,760		(123)		4,952		(276)		9,712		(399)
Total debt securities		326,045		(3,187)		26,574		(613)		352,619		(3,800)
Total equity securities		12,444		(4,185)		-		-		12,444		(4,185)
Total other investments		3,461		(302)		-		-		3,461		(302)
Total investments	$	341,950	$	(7,674)	$	26,574	$	(613)	$	368,524	$	(8,287)
	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 March 31, 2018 and December 31, 2017 are as follows (in thousands):

	March 31,		December 31,
	2018		2017
Investment Type
Equity warrant	$	3,461	$	3,824
Total other investments	$	3,461	$	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	$	130,123	$	129,929
Due after one year through five years		276,426		277,296
Due after five years through ten years		134,924		135,509
Due after ten years		38,989		38,464
Mortgage-backed		15,019		14,648
	$	595,481	$	595,846