Investment Securities (Tables)

9 Months Ended

Sep. 30, 2022

Investments Debt And Equity Securities [Abstract]

Available for Sale and Held for Maturity Securities

The amortized cost, gross unrealized gains and losses and estimated fair values for available-for-sale and held-to-maturity securities by major security type at September 30, 2022 and December 31, 2021 were as follows (in thousands):

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
September 30, 2022
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	256,478	$	—	$	(33,747	)	$	222,731
Obligations of states and political subdivisions		360,622		35		(74,549	)		286,108
Mortgage-backed securities: GSE residential		763,882		7		(123,495	)		640,394
Other securities		85,948		1		(4,394	)		81,555
Total available-for-sale	$	1,466,930	$	43	$	(236,185	)	$	1,230,788
Held-to-maturity:
Other investments	$	2,930	$	—	$	—		$	2,930
Total held-to-maturity	$	2,930	$	—	$	—		$	2,930
December 31, 2021
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	208,598	$	80	$	(4,863	)	$	203,815
Obligations of states and political subdivisions		383,991		12,123		(657	)		395,457
Mortgage-backed securities: GSE residential		799,456		4,292		(12,710	)		791,038
Other securities		30,546		671		(105	)		31,112
Total available-for-sale	$	1,422,591	$	17,166	$	(18,335	)	$	1,421,422
Held-to-maturity:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	5,001	$	5	$	—		$	5,006
Other investments		2,029		—		—			2,029
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	7,030	$	5	$	—		$	7,035

Realized Gains and Losses From Sale of Securities

Realized gains and losses resulting from sales of securities were as follows during the three and nine months ended September 30, 2022 and 2021 (in thousands):

	Three months September 30,					Nine months September 30,
	2022			2021		2022			2021
Gross gains	$	191		$	11	$	193		$	88
Gross losses		(112	)		—		(112	)		—

Investments Classified by Contractual Maturity Date

The following table indicates the expected maturities of investment securities classified as available-for-sale presented at fair value, and held-to-maturity presented at amortized cost, at September 30, 2022 and the weighted average yield for each range of maturities (dollars in thousands):

	One year or less			After 1 through 5 years			After 5 through 10 years			After ten years			Total
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	159,663		$	53,511		$	9,557		$	—		$	222,731
Obligations of state and political subdivisions		24,140			75,195			185,717			1,056			286,108
Mortgage-backed securities: GSE residential		3,831			90,744			544,195			1,624			640,394
Other securities		19,480			61,306			769			—			81,555
Total available-for-sale investments	$	207,114		$	280,756		$	740,238		$	2,680		$	1,230,788
Weighted average yield		1.56	%		3.17	%		1.76	%		2.88	%		2.03	%
Full tax-equivalent yield		1.68	%		3.44	%		1.93	%		3.40	%		2.21	%
Held to maturity:
Other investments	$	—		$	—		$	—		$	2,930		$	2,930
Total held-to-maturity	$	—		$	—		$	—		$	2,930		$	2,930
Weighted average yield		—	%		—	%		—	%		—	%		—	%
Full tax-equivalent yield		—	%		—	%		—	%		—	%		—	%

Fair Value of Investments with Sustained Gross Unrealized Losses

The following table presents the aging of gross unrealized losses and fair value by investment category as of September 30, 2022 and December 31, 2021 (in thousands):

	Less than 12 months					12 months or more					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
September 30, 2022
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	89,341	$	(8,618	)	$	132,392	$	(25,129	)	$	221,733	$	(33,747	)
Obligations of states and political subdivisions		235,842		(57,209	)		37,212		(17,340	)		273,054		(74,549	)
Mortgage-backed securities: GSE residential		260,199		(40,477	)		379,400		(83,018	)		639,599		(123,495	)
Other securities		64,075		(3,823	)		5,979		(571	)		70,054		(4,394	)
Total	$	649,457	$	(110,127	)	$	554,983	$	(126,058	)	$	1,204,440	$	(236,185	)
December 31, 2021
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	48,316	$	(1,927	)	$	139,846	$	(2,936	)	$	188,162	$	(4,863	)
Obligations of states and political subdivisions		61,535		(657	)		—		—			61,535		(657	)
Mortgage-backed securities: GSE residential		562,699		(11,019	)		46,504		(1,691	)		609,203		(12,710	)
Other securities		7,976		(105	)		—		—			7,976		(105	)
Total	$	680,526	$	(13,708	)	$	186,350	$	(4,627	)	$	866,876	$	(18,335	)