INVESTMENTS (Tables)

6 Months Ended

Jun. 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)
June 30, 2017
Debt securities  - available-for-sale:
United States government obligations and authorities	$	85,643	$	462	$	484	$	85,621
Obligations of states and political subdivisions		86,295		852		228		86,919
Corporate		194,484		2,577		328		196,733
International		14,483		164		10		14,637
		380,905		4,055		1,050		383,910
Debt securities  - held-to-maturity:
United States government obligations and authorities		4,165		21		109		4,077
Corporate		1,190		27		—		1,217
International		66		1		—		67
		5,421		49		109		5,361
Equity securities		40,202		5,966		723		45,445
Total investments	$	426,528	$	10,070	$	1,882	$	434,716

	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				Six Months Ended
	June 30,				June 30,
	2017		2016		2017		2016
	(in thousands)				(in thousands)
Gross realized gains:
Debt securities	$	304	$	624	$	873	$	1,927
Equity securities		2,735		417		3,290		1,155
Total gross realized gains		3,039		1,041		4,163		3,082
Gross realized losses:
Debt securities		(118)		(55)		(1,209)		(595)
Equity securities		(273)		(979)		(411)		(1,553)
Total gross realized losses		(391)		(1,034)		(1,620)		(2,148)
Net realized gains on investments	$	2,648	$	7	$	2,543	$	934

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

	June 30, 2017				December 31, 2016
	Amortized				Amortized
	Cost		Fair Value		Cost		Fair Value
Securities with maturity dates:	(in thousands)
Debt securities, available-for-sale:
One year or less	$	38,343	$	38,399	$	46,189	$	46,231
Over one through five years		181,014		182,264		177,982		177,899
Over five through ten years		160,332		162,048		150,557		148,783
Over ten years		1,216		1,199		1,916		1,843
		380,905		383,910		376,644		374,756
Debt securities, held-to-maturity:
One year or less		135		135		170		170
Over one through five years		1,858		1,892		1,719		1,750
Over five through ten years		3,428		3,334		3,662		3,553
		5,421		5,361		5,551		5,473
Total	$	386,326	$	389,271	$	382,195	$	380,229

Summary of Net Investment Income

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2017		2016		2017		2016
	(in thousands)
Interest income	$	2,411	$	1,984	$	4,581	$	3,837
Dividends income		149		210		297		397
Net investment income	$	2,560	$	2,194	$	4,878	$	4,234

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
June 30, 2017					(in thousands)
Debt securities - available-for-sale:
United States government obligations
and authorities	$	48,333	$	479	$	98	$	5	$	48,431	$	484
Obligations of states and political subdivisions		24,012		228		—		—		24,012		228
Corporate		43,646		320		930		8		44,576		328
International		1,774		10		—		—		1,774		10
		117,765		1,037		1,028		13		118,793		1,050
Equity securities		9,010		631		696		92		9,706		723
Total investments	$	126,775	$	1,668	$	1,724	$	105	$	128,499	$	1,773

	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