Investments (Tables)

9 Months Ended

Sep. 30, 2018

Gross Unrealized Gains and Losses and Amortized Cost and Fair Value of Investments Classified as Held-to-maturity

The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as held-to-maturity at September 30, 2018 are summarized as follows:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
States and political subdivisions	$	430,408	$	3,053	$	(4,773	)	$	428,688
Corporate bonds		95,731		9		(879	)		94,861
U.S. agency-based mortgage-backed securities		8,535		359		(87	)		8,807
U.S. Treasury securities and obligations of U.S.    government agencies		67,052		325		(966	)		66,411
Asset-backed securities		1,104		24		(10	)		1,118
Totals	$	602,830	$	3,770	$	(6,715	)	$	599,885

The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as held-to-maturity at December 31, 2017 are summarized as follows:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
States and political subdivisions	$	460,428	$	9,628	$	(955	)	$	469,101
Corporate bonds		100,024		190		(167	)		100,047
U.S. agency-based mortgage-backed securities		10,260		625		(40	)		10,845
U.S. Treasury securities and obligations    of U.S. government agencies		57,657		548		(198	)		58,007
Asset-backed securities		1,299		25		(15	)		1,309
Totals	$	629,668	$	11,016	$	(1,375	)	$	639,309

Gross Unrealized Gains and Losses and Cost or Amortized Cost and Fair Value of Investments Classified as Available-for-sale

The gross unrealized gains and losses on, and the cost or amortized cost and fair value of, those investments classified as available-for-sale at September 30, 2018 are summarized as follows:

	Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
States and political subdivisions	$	229,007	$	2,334	$	(3,854	)	$	227,487
Corporate bonds		163,834		43		(929	)		162,948
U.S. agency-based mortgage-backed securities		13,256		—		(476	)		12,780
U.S. Treasury securities and obligations    of U.S. government agencies		67,218		—		(2,414	)		64,804
Totals	$	473,315	$	2,377	$	(7,673	)	$	468,019

The gross unrealized gains and losses on, and the cost or amortized cost and fair value of, those investments classified as available-for-sale at December 31, 2017 are summarized as follows:

	Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
States and political subdivisions	$	244,898	$	6,819	$	(577	)	$	251,140
Corporate bonds		130,210		224		(212	)		130,222
U.S. agency-based mortgage-backed securities		18,813		—		(799	)		18,014
U.S. Treasury securities and obligations    of U.S. government agencies		67,315		29		(1,126	)		66,218
Total fixed maturity		461,236		7,072		(2,714	)		465,594
Equity securities		8,503		779		—			9,282
Totals	$	469,739	$	7,851	$	(2,714	)	$	474,876

Investment Securities Continuous Unrealized Loss Position

The following table summarizes the fair value and gross unrealized losses on securities, aggregated by major investment category and length of time that the individual securities have been in a continuous unrealized loss position:

	Less Than 12 Months				12 Months or Greater				Total
	Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses		Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses		Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses
	(in thousands)
September 30, 2018
Held-to-Maturity
Fixed maturity securities:
States and political subdivisions	$	237,284	$	3,737	$	35,373	$	1,036	$	272,657	$	4,773
Corporate bonds		67,454		584		21,100		295		88,554		879
U.S. agency-based mortgage-backed securities		1,962		65		482		22		2,444		87
U.S. Treasury securities and obligations    of U.S. government agencies		31,676		443		29,054		523		60,730		966
Asset-backed securities		510		8		38		2		548		10
Total held-to-maturity securities		338,886		4,837		86,047		1,878		424,933		6,715
Available-for-Sale
Fixed maturity securities:
States and political subdivisions	$	97,971	$	2,118	$	21,048	$	1,736	$	119,019	$	3,854
Corporate bonds		133,712		772		9,615		157		143,327		929
U.S. agency-based mortgage-backed securities		8,356		288		4,424		188		12,780		476
U.S. Treasury securities and obligations    of U.S. government agencies		8,376		296		56,428		2,118		64,804		2,414
Total available-for-sale securities		248,415		3,474		91,515		4,199		339,930		7,673
Total	$	587,301	$	8,311	$	177,562	$	6,077	$	764,863	$	14,388

	Less Than 12 Months				12 Months or Greater				Total
	Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses		Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses		Fair Value of Investments with Unrealized Losses		Gross Unrealized Losses
	(in thousands)
December 31, 2017
Held-to-Maturity
Fixed maturity securities:
States and political subdivisions	$	110,698	$	654	$	19,895	$	301	$	130,593	$	955
Corporate bonds		56,425		156		4,121		11		60,546		167
U.S. agency-based mortgage-backed securities		2,798		40		—		—		2,798		40
U.S. Treasury securities and obligations    of U.S. government agencies		48,153		122		3,948		76		52,101		198
Asset-backed securities		—		—		967		15		967		15
Total held-to-maturity securities		218,074		972		28,931		403		247,005		1,375
Available-for-Sale
Fixed maturity securities:
States and political subdivisions	$	23,365	$	86	$	19,153	$	491	$	42,518	$	577
Corporate bonds		82,795		171		5,888		41		88,683		212
U.S. agency-based mortgage-backed securities		14,686		59		3,328		740		18,014		799
U.S. Treasury securities and obligations    of U.S. government agencies		14,730		204		47,716		922		62,446		1,126
Total available-for-sale securities		135,576		520		76,085		2,194		211,661		2,714
Total	$	353,650	$	1,492	$	105,016	$	2,597	$	458,666	$	4,089

Held-to-Maturity Securities [Member]

Summary of Amortized Cost and Fair Value of Investments in Fixed Maturity Securities, by Contractual Maturity

A summary of the amortized cost and fair value of investments in fixed maturity securities, classified as held-to-maturity at September 30, 2018, by contractual maturity, is as follows:

	Amortized Cost		Fair Value
	(in thousands)
Maturity:
Within one year	$	80,180	$	80,293
After one year through five years		260,292		259,523
After five years through ten years		85,673		84,902
After ten years		167,046		165,242
U.S. agency-based mortgage-backed securities		8,535		8,807
Asset-backed securities		1,104		1,118
Totals	$	602,830	$	599,885

Available-for-Sale Securities [Member]

Summary of Amortized Cost and Fair Value of Investments in Fixed Maturity Securities, by Contractual Maturity

A summary of the amortized cost and fair value of investments in fixed maturity securities, classified as available-for-sale at September 30, 2018, by contractual maturity, is as follows:

	Amortized Cost		Fair Value
	(in thousands)
Maturity:
Within one year	$	73,298	$	73,137
After one year through five years		165,853		163,342
After five years through ten years		44,355		43,378
After ten years		176,553		175,382
U.S. agency-based mortgage-backed securities		13,256		12,780
Totals	$	473,315	$	468,019