Investments (Tables)

12 Months Ended

Dec. 31, 2020

Investments [Abstract]

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

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

			Gross		Gross
		Cost/Amortized	Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
As of December 31, 2020
U.S. Treasury securities and obligations of U.S. Government	$	179,259	$	487	$	-	$	179,746
Corporate bonds		214,666		5,086		(384)		219,368
Corporate bank loans		53,650		3		(871)		52,782
Municipal bonds		49,833		756		(50)		50,539
Mortgage-backed		4,759		114		(29)		4,844
Total debt securities		502,167		6,446		(1,334)		507,279
Total equity securities		26,988		5,648		(3,248)		29,388
Total other investments		—		—		—		—
Total investments	$	529,155	$	12,094	$	(4,582)	$	536,667
As of December 31, 2019
U.S. Treasury securities and obligations of U.S. Government	$	66,441	$	162	$	(3)	$	66,600
Corporate bonds		297,601		3,387		(163)		300,825
Corporate bank loans		115,669		556		(468)		115,757
Municipal bonds		81,787		1,531		(48)		83,270
Mortgage-backed		8,000		46		(219)		7,827
Total debt securities		569,498		5,682		(901)		574,279
Total equity securities		71,895		35,028		(7,708)		99,215
Total other investments		3,763		—		(1,594)		2,169
Total investments	$	645,156	$	40,710	$	(10,203)	$	675,663

Major Categories of Investment Income

Major categories of net investment income are summarized as follows (in thousands):

	Twelve Months Ended December 31,
	2020		2019
U.S. Treasury securities and obligations of U.S. Government	$	885	$	916
Corporate bonds		7,223		7,317
Corporate bank loans		1,688		6,028
Municipal bonds		2,347		3,907
Mortgage-backed		192		311
Equity securities		1,369		2,364
Cash and cash equivalents		—		766
		13,704		21,609
Investment expenses		(784)		(1,005)
Investment income, net of expenses	$	12,920	$	20,604

Major Categories of Net Investment (Losses) Gains on Investments

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

	Year Ended December 31,
	2020		2019
U.S. Treasury securities and obligations of U.S. Government	$	(3)	$	—
Corporate bonds		959		235
Corporate bank loans		40		(34)
Municipal bonds		1,397		4,270
Mortgage-backed		—		—
Equity securities		3,472		(7)
Other investments		(3,740)		—
Gain on investments		2,125		4,464
Other-than-temporary impairments		(1,692)		—
Unrealized (losses) gains on equity securities		(24,921)		15,133
Unrealized gains on other investments		1,594		1,021
Investment (losses) gains, net	$	(22,894)	$	20,618

Summary of Gross 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 December 31, 2020 and December 31, 2019 (in thousands):

	As of December 31, 2020
	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		7,801		(186)		3,556		(198)		11,357		(384)
Corporate bank loans		45,233		(559)		4,144		(312)		49,377		(871)
Municipal bonds		2,859		(33)		1,154		(17)		4,013		(50)
Mortgage-backed		635		(25)		14		(4)		649		(29)
Total debt securities		56,528		(803)		8,868		(531)		65,396		(1,334)
Total equity securities		9,572		(1,610)		1,848		(1,638)		11,420		(3,248)
Total other investments		—		—		—		—		—		—
Total investments	$	66,100	$	(2,413)	$	10,716	$	(2,169)	$	76,816	$	(4,582)

	As of December 31, 2019
	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	$	—	$	—	$	5,513	$	(3)	$	5,513	$	(3)
Corporate bonds		27,268		(144)		1,150		(19)		28,418		(163)
Corporate bank loans		9,000		(41)		10,228		(427)		19,228		(468)
Municipal bonds		4,808		(29)		1,618		(19)		6,426		(48)
Mortgage-backed		1,712		(101)		562		(118)		2,274		(219)
Total debt securities		42,788		(315)		19,071		(586)		61,859		(901)
Total equity securities		10,905		(2,363)		6,093		(5,345)		16,998		(7,708)
Total other investments		—		—		2,169		(1,594)		2,169		(1,594)
Total investments	$	53,693	$	(2,678)	$	27,333	$	(7,525)	$	81,026	$	(10,203)

Carrying Value of Other Invested Assets Portfolio

	December 31,		December 31,
	2020		2019
Investment Type
Equity warrant	$	—	$	2,169
Total other investments	$	—	$	2,169

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

	Amortized Cost		Fair Value
	(in thousands)
Due in one year or less	$	255,768	$	257,246
Due after one year through five years		200,343		203,625
Due after five years through ten years		28,632		28,363
Due after ten years		12,665		13,202
Mortgage-backed		4,759		4,843
	$	502,167	$	507,279