Investments (Tables)

3 Months Ended

Mar. 31, 2024

Gross Unrecognized Gains and Losses and Cost or Amortized Cost, Allowance for Credit Losses, Carrying Amount and Fair Value of Investments Classified as Held-to-Maturity

The amortized cost, allowance for credit losses, carrying amount, gross unrecognized gains and losses, and the fair value of those investments classified as held-to-maturity at March 31, 2024 are summarized as follows:

	Amortized Cost		Allowance for Credit Losses			Carrying Amount		Gross Unrecognized Gains		Gross Unrecognized Losses			Fair Value
	(in thousands)
States and political subdivisions	$	412,900	$	(37	)	$	412,863	$	2,804	$	(13,871	)	$	401,796
Corporate bonds		48,164		(126	)		48,038		—		(2,078	)		45,960
U.S. agency-based mortgage-backed securities		3,183		—			3,183		19		(150	)		3,052
U.S. Treasury securities and obligations    of U.S. government agencies		11,209		—			11,209		14		(379	)		10,844
Asset-backed securities		31		(2	)		29		—		—			29
Totals	$	475,487	$	(165	)	$	475,322	$	2,837	$	(16,478	)	$	461,681

The amortized cost, allowance for credit losses, carrying amount, gross unrecognized gains and losses, and the fair value of those investments classified as held-to-maturity at December 31, 2023 are summarized as follows:

	Amortized Cost		Allowance for Credit Losses			Carrying Amount		Gross Unrecognized Gains		Gross Unrecognized Losses			Fair Value
	(in thousands)
States and political subdivisions	$	416,916	$	(38	)	$	416,878	$	4,166	$	(12,074	)	$	408,970
Corporate bonds		52,321		(142	)		52,179		—		(2,231	)		49,948
U.S. agency-based mortgage-backed securities		3,297		—			3,297		25		(123	)		3,199
U.S. Treasury securities and obligations    of U.S. government agencies		11,186		—			11,186		26		(273	)		10,939
Asset-backed securities		37		(2	)		35		1		—			36
Totals	$	483,757	$	(182	)	$	483,575	$	4,218	$	(14,701	)	$	473,092

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

The amortized cost, gross unrealized gains and losses, fair value, and the allowance for credit losses of those investments classified as available-for-sale at March 31, 2024 are summarized as follows:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Allowance for Credit Losses
	(in thousands)
States and political subdivisions	$	122,545	$	260	$	(7,013	)	$	115,792	$	—
Corporate bonds		159,284		1,509		(4,042	)		156,751		—
U.S. agency-based mortgage-backed securities		5,032		—		(502	)		4,530		—
U.S. Treasury securities and obligations    of U.S. government agencies		14,830		—		(1,230	)		13,600		—
Totals	$	301,691	$	1,769	$	(12,787	)	$	290,673	$	—

The amortized cost, gross unrealized gains and losses, fair value, and the allowance for credit losses of those investments classified as available-for-sale at December 31, 2023 are summarized as follows:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Allowance for Credit Losses
	(in thousands)
States and political subdivisions	$	138,031	$	583	$	(6,719	)	$	131,895	$	—
Corporate bonds		168,134		2,105		(3,486	)		166,753		—
U.S. agency-based mortgage-backed securities		5,190		—		(445	)		4,745		—
U.S. Treasury securities and obligations    of U.S. government agencies		14,816		—		(1,145	)		13,671		—
Totals	$	326,171	$	2,688	$	(11,795	)	$	317,064	$	—

Gross Unrealized Gains and Losses and Cost of Equity

The cost, gross unrealized gains and losses, and the fair value of equity securities at March 31, 2024 are summarized as follows:

	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Equity securities:
Domestic common stock	$	44,045	$	17,878	$	—	$	61,923
Total equity securities	$	44,045	$	17,878	$	—	$	61,923

The cost, gross unrealized gains and losses, and the fair value of equity securities at December 31, 2023 are summarized as follows:

	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Equity securities:
Domestic common stock	$	44,046	$	13,101	$	—	$	57,147
Total equity securities	$	44,046	$	13,101	$	—	$	57,147

Investment Securities Continuous Unrealized Loss Position

The following table summarizes the fair value and gross unrealized losses on securities classified as available-for-sale, aggregated by major investment category and length of time that the individual securities have been in a continuous unrealized loss position as of March 31, 2024:

	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)
March 31, 2024
Available-for-Sale
States and political subdivisions	$	61,604	$	4,900	$	25,175	$	2,113	$	86,779	$	7,013
Corporate bonds		79,904		2,613		35,075		1,429		114,979		4,042
U.S. agency-based mortgage-backed securities		4,293		464		237		38		4,530		502
U.S. Treasury securities and obligations    of U.S. government agencies		—		—		13,600		1,230		13,600		1,230
Total available-for-sale securities	$	145,801	$	7,977	$	74,087	$	4,810	$	219,888	$	12,787

The following table summarizes the fair value and gross unrealized losses on securities classified as available-for-sale, aggregated by major investment category and length of time that the individual securities have been in a continuous unrealized loss position as of December 31, 2023:

	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, 2023
Available-for-Sale
States and political subdivisions	$	14,115	$	111	$	72,358	$	6,608	$	86,473	$	6,719
Corporate bonds		26,178		96		93,538		3,390		119,716		3,486
U.S. agency-based mortgage-backed securities		—		—		4,745		445		4,745		445
U.S. Treasury securities and obligations    of U.S. government agencies		—		—		13,672		1,145		13,672		1,145
Total available-for-sale securities	$	40,293	$	207	$	184,313	$	11,588	$	224,606	$	11,795

Changes in Allowance for Credit Losses by Major Security Type of Investments Classified as Held-to-Maturity

The following table illustrates the changes in the allowance for credit losses by major security type of the investments classified as held-to-maturity for the quarter ended March 31, 2024.

	States and Political Subdivisions			Corporate Bonds			U.S. Agency -Based Mortgage- Backed Securities		U.S. Treasury Securities and Obligations of U.S. Government Agencies		Asset-Backed Securities		Totals
	(in thousands)
Balance at December 31, 2023	$	38		$	142		$	—	$	—	$	2	$	182
Provision for credit loss benefit		(1	)		(16	)		—		—		—		(17	)
Balance at March 31, 2024	$	37		$	126		$	—	$	—	$	2	$	165

Schedule of Amortized Cost Held-to-Maturity Securities Aggregated By Credit Quality Indicator

The table below presents the amortized cost of held-to-maturity securities aggregated by credit quality indicator as of March 31, 2024.

	States and Political Subdivisions		Corporate Bonds		U.S. Agency -Based Mortgage- Backed Securities		U.S. Treasury Securities and Obligations of U.S. Government Agencies		Asset-Backed Securities		Totals
	Amortized cost
	(in thousands)
AAA/AA/A ratings	$	409,955	$	18,723	$	3,183	$	11,209	$	18	$	443,088
Baa/BBB ratings		2,945		29,441		—		—		13		32,399
B ratings		—		—		—		—		—		—
Total	$	412,900	$	48,164	$	3,183	$	11,209	$	31	$	475,487

Held-to-Maturity Securities [Member]

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

A summary of the carrying amounts and fair value of investments in fixed maturity securities classified as held-to-maturity, by contractual maturity, is as follows:

	March 31, 2024				December 31, 2023
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
	(in thousands)
Maturity:
Within one year	$	64,898	$	64,232	$	64,129	$	63,703
After one year through five years		126,220		120,555		136,854		131,396
After five years through ten years		116,791		111,569		114,990		110,814
After ten years		164,201		162,244		164,270		163,944
U.S. agency-based mortgage-backed securities		3,183		3,052		3,297		3,199
Asset-backed securities		29		29		35		36
Totals	$	475,322	$	461,681	$	483,575	$	473,092

Available-for-Sale Securities [Member]

Summary of Carrying Amount, 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, by contractual maturity, is as follows:

	March 31, 2024				December 31, 2023
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
	(in thousands)
Maturity:
Within one year	$	19,402	$	19,297	$	25,995	$	25,875
After one year through five years		107,593		103,291		106,178		102,201
After five years through ten years		74,338		71,695		82,664		80,911
After ten years		95,326		91,860		106,144		103,332
U.S. agency-based mortgage-backed securities		5,032		4,530		5,190		4,745
Totals	$	301,691	$	290,673	$	326,171	$	317,064