INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2017

Investments [Abstract]

Unrealized Gain (Loss) on Investments

The difference between amortized cost or cost and estimated fair value and gross unrealized gains and losses, by major investment category, consisted of the following:

໿

	Amortized		Gross		Gross
	Cost		Unrealized		Unrealized
	or Cost		Gains		Losses		Fair Value
	(In thousands)
December 31, 2017
Debt securities - available-for-sale:
United States government obligations and authorities	$	98,739	$	244	$	846	$	98,137
Obligations of states and political subdivisions	66,319		325		378		66,266
Corporate securities	239,435		2,233		749		240,919
International securities	17,807		136		27		17,916
	422,300		2,938		2,000		423,238
Debt securities - held-to-maturity:
United States government obligations and authorities	4,160		9		106		4,063
Corporate securities	1,123		21		—		1,144
International securities	66		1		—		67
	5,349		31		106		5,274
Equity securities	14,085		1,628		279		15,434
Total investments	$	441,734	$	4,597	$	2,385	$	443,946

	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

Net realized gains, by major investment category, consisted of the following:

໿

	Year Ended December 31,
	2017			2016			2015
	(In thousands)
Gross realized gains:
Debt securities	$	1,814		$	3,208		$	1,272
Equity securities	9,944			4,264			4,959
Total gross realized gains	11,758			7,472			6,231
Gross realized losses:
Debt securities	(1,671		)	(1,614		)	(805		)
Equity securities	(1,539		)	(2,813		)	(1,810		)
Total gross realized losses	(3,210		)	(4,427		)	(2,615		)
Net realized gains on investments	$	8,548		$	3,045		$	3,616

Investments Classified by Contractual Maturity Date

Amortized cost and estimated fair value of debt securities, by contractual maturity, consisted of the following:

	December 31, 2017
	Amortized
	Cost		Fair Value
Securities with maturity dates:	(In thousands)
Debt securities, available-for-sale:
One year or less	$	45,949	$	45,879
Over one through five years	194,427		194,463
Over five through ten years	177,657		178,664
Over ten years	4,267		4,232
	422,300		423,238
Debt securities, held-to-maturity:
One year or less	180		180
Over one through five years	4,097		4,028
Over five through ten years	1,072		1,066
	5,349		5,274
Total	$	427,649	$	428,512

Summary of Net Investment Income

Net investment income consisted of the following: ໿

	Year Ended December 31,
	2017		2016		2015
	(In thousands)
Interest income	$	9,776	$	7,920	$	6,638
Dividends income	478		1,143		588
Net investment income	$	10,254	$	9,063	$	7,226

Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value

Gross unrealized losses and related fair values for debt and equity securities, grouped by duration of time in a continuous unrealized loss position, consisted of the following:

	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, 2017					(In thousands)
Debt securities - available-for-sale:
United States government obligations
and authorities	$	52,368	$	517	$	19,287	$	329	$	71,655	$	846
Obligations of states and political subdivisions	32,030		221		5,676		157		37,706		378
Corporate	109,780		625		6,452		124		116,232		749
International	8,935		27		25		—		8,960		27
	203,113		1,390		31,440		610		234,553		2,000
Equity securities	4,312		279		—		—		4,312		279
Total investments	$	207,425	$	1,669	$	31,440	$	610	$	238,865	$	2,279

	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