INVESTMENTS (Tables)

9 Months Ended

Sep. 30, 2017

INVESTMENTS [Abstract]

Summary of Amortized Cost and Fair Value of Debt and Equity Securities

	Amortized		Gross		Gross
	Cost		Unrealized		Unrealized
	or Cost		Gains		Losses		Fair Value
	(in thousands)
September 30, 2017
Debt securities  - available-for-sale:
United States government obligations and authorities	$	116,390	$	421	$	601	$	116,210
Obligations of states and political subdivisions		72,372		792		165		72,999
Corporate		216,923		2,897		419		219,401
International		13,558		193		2		13,749
		419,243		4,303		1,187		422,359
Debt securities  - held-to-maturity:
United States government obligations and authorities		4,156		18		91		4,083
Corporate		1,189		28		—		1,217
International		65		1		—		66
		5,410		47		91		5,366
Equity securities		14,531		1,312		268		15,575
Total investments	$	439,184	$	5,662	$	1,546	$	443,300

	Amortized		Gross		Gross
	Cost		Unrealized		Unrealized
	or Cost		Gains		Losses			Fair Value
	(in thousands)
December 31, 2016
Debt securities  - available-for-sale:
United States government obligations and authorities	$	62,881	$	177	$	853	$	62,205
Obligations of states and political subdivisions		152,823		427		2,067		151,183
Corporate		149,053		1,347		895		149,505
International		11,887		95		119		11,863
		376,644		2,046		3,934		374,756
Debt securities  - held-to-maturity:
United States government obligations and authorities		4,163		22		118		4,067
Corporate		1,317		20		2		1,335
International		71		—		—		71
		5,551		42		120		5,473
Equity securities		24,163		5,500		288		29,375
Total investments	$	406,358	$	7,588	$	4,342	$	409,604

Net Realized Gains (Losses) by Major Investment Category

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2017		2016		2017		2016
	(in thousands)				(in thousands)
Gross realized gains:
Debt securities	$	618	$	897	$	1,471	$	2,822
Equity securities		6,527		597		9,776		1,752
Total gross realized gains		7,145		1,494		11,247		4,574
Gross realized losses:
Debt securities		(103)		(20)		(1,293)		(614)
Equity securities		(941)		(348)		(1,310)		(1,900)
Total gross realized losses		(1,044)		(368)		(2,603)		(2,514)
Net realized gains on investments	$	6,101	$	1,126	$	8,644	$	2,060

Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity

	September 30, 2017
	Amortized
	Cost		Fair Value
Securities with maturity dates:	(in thousands)
Debt securities, available-for-sale:
One year or less	$	37,940	$	37,968
Over one through five years		196,630		198,180
Over five through ten years		182,560		184,199
Over ten years		2,113		2,012
		419,243		422,359
Debt securities, held-to-maturity:
One year or less		170		170
Over one through five years		4,114		4,065
Over five through ten years		1,126		1,131
		5,410		5,366
Total	$	424,653	$	427,725

Summary of Net Investment Income

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2017		2016		2017		2016
	(in thousands)
Interest income	$	2,492	$	1,963	$	7,073	$	5,801
Dividends income		111		201		408		597
Net investment income	$	2,603	$	2,164	$	7,481	$	6,398

Gross Unrealized Losses and Related Fair Values for Debt and Equity Securities, Grouped by Duration of Time in Continuous Unrealized Loss Position

	Less than 12 months				12 months or longer				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
September 30, 2017					(in thousands)
Debt securities - available-for-sale:
United States government obligations
and authorities	$	67,924	$	527	$	5,820	$	74	$	73,744	$	601
Obligations of states and political subdivisions		15,454		135		2,966		30		18,420		165
Corporate		58,838		340		3,971		79		62,809		419
International		1,383		2		—		—		1,383		2
		143,599		1,004		12,757		183		156,356		1,187
Equity securities		3,478		267		242		1		3,720		268
Total investments	$	147,077	$	1,271	$	12,999	$	184	$	160,076	$	1,455

	Less than 12 months				12 months or longer				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
December 31, 2016					(in thousands)
Debt securities - available-for-sale:
United States government obligations
and authorities	$	45,255	$	850	$	111	$	3	$	45,366	$	853
Obligations of states and political subdivisions		103,724		2,066		1,007		1		104,731		2,067
Corporate		59,970		864		2,427		31		62,397		895
International		5,925		119		5		—		5,930		119
		214,874		3,899		3,550		35		218,424		3,934
Equity securities		4,701		253		434		35		5,135		288
Total investments	$	219,575	$	4,152	$	3,984	$	70	$	223,559	$	4,222