Investments (Tables)

3 Months Ended

Mar. 31, 2024

Investments [Abstract]

Debt Securities, Available-for-sale

The aggregate carrying and approximate fair values of investment securities follow (in thousands).  Fair values are based on quoted market prices, where available.  If quoted market prices are not available, fair values are based on quoted market prices of comparable financial instruments.

	March 31, 2024								December 31, 2023
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Securities available-for-sale:
Obligations of states and
political subdivisions	$	227,434	$	217	$	17,127	$	210,524	$	228,456	$	371	$	16,089	$	212,738
Mortgage-backed securities:
U.S. government agencies	1,236,587		1,316		138,106		1,099,797		1,211,484		2,362		125,753		1,088,093
Private label	6,981		—		284		6,697		6,997		—		293		6,704
Trust preferred securities	4,600		—		151		4,449		4,599		—		321		4,278
Corporate securities	27,970		52		1,832		26,190		28,009		137		1,822		26,324
Total Securities Available-for-Sale	$	1,503,572	$	1,585	$	157,500	$	1,347,657	$	1,479,545	$	2,870	$	144,278	$	1,338,137

Gross Unrealized Losses And Fair Value Of Investments

The following table shows the gross unrealized losses and fair value of the Company’s investments aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands):

	March 31, 2024
	Less Than Twelve Months				Twelve Months or Greater				Total
	Estimated Fair Value		Unrealized Loss		Estimated Fair Value		Unrealized Loss		Estimated Fair Value		Unrealized Loss
Securities available-for-sale:
Obligations of states and political subdivisions	$	14,599	$	200	$	181,421	$	16,927	$	196,020	$	17,127
Mortgage-backed securities:
U.S. Government agencies	265		8,546		724,601		129,560		724,866		138,106
Private label	1,849		22		4,848		262		6,697		284
Trust preferred securities	—		—		4,449		151		4,449		151
Corporate securities	—		—		24,551		1,832		24,551		1,832
Total available-for-sale	$	16,713	$	8,768	$	939,870	$	148,732	$	956,583	$	157,500

	December 31, 2023
	Less Than Twelve Months				Twelve Months or Greater				Total
	Estimated Fair Value		Unrealized Loss		Estimated Fair Value		Unrealized Loss		Estimated Fair Value		Unrealized Loss
Securities available-for-sale:
Obligations of states and political subdivisions	$	7,591	$	66	$	180,560	$	16,023	$	188,151	$	16,089
Mortgage-backed securities:
U.S. Government agencies	2,046		10,271		740,911		115,482		742,957		125,753
Private label	—		—		4,838		293		4,838		293
Trust preferred securities	—		—		4,278		321		4,278		321
Corporate securities	—		—		24,609		1,822		24,609		1,822
Total available-for-sale	$	9,637	$	10,337	$	955,196	$	133,941	$	964,833	$	144,278

Amortized Cost And Estimated Fair Value Of Debt Securities By Contractual Maturity

The amortized cost and estimated fair value of debt securities at March 31, 2024, by contractual maturity, is shown in the following table (in thousands).  Expected maturities will differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties.  Mortgage-backed securities have been allocated to their respective maturity groupings based on their contractual maturity.

	Amortized Cost		Estimated Fair Value
Available-for-Sale Debt Securities
Due in one year or less	$	2,630	$	2,598
Due after one year through five years	108,133		102,535
Due after five years through ten years	406,455		375,247
Due after ten years	986,354		867,277
Total	$	1,503,572	$	1,347,657

Gross Gains And Losses Realized

Proceeds from sales, gross gains and gross losses recognized by the Company from investment security transactions are summarized in the table below (in thousands):

	Three months ended March 31,
	2024		2023
Proceeds on sales of available for sale securities	$	—	$	84,940
Gross realized gains on securities sold	$	—	$	975
Gross realized losses on securities sold	(1)		(202)
Net realized investment security gains	$	(1)	$	773
Gross unrealized gains recognized on equity securities still held	$	63	$	463
Gross unrealized losses recognized on equity securities still held	(215)		(102)
Net unrealized (losses) gains recognized on equity securities still held	$	(152)	$	361