Investment Securities (Tables)

9 Months Ended

Sep. 30, 2021

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, 2021 and December 31, 2020 were as follows (in thousands):

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
September 30, 2021
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	194,162	$	308	$	(2,786	)	$	191,684
Obligations of states and political subdivisions		328,394		11,310		(960	)		338,744
Mortgage-backed securities: GSE residential		783,400		6,300		(7,085	)		782,615
Other securities		33,076		883		(36	)		33,923
Total available-for-sale	$	1,339,032	$	18,801	$	(10,867	)	$	1,346,966
Held-to-maturity:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	5,004	$	31	$	—		$	5,035
Other securities		2,022		—		—			2,022
Total held-to-maturity	$	7,026	$	31	$	—		$	7,057
December 31, 2020
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	127,067	$	790	$	(788	)	$	127,069
Obligations of states and political subdivisions		237,886		11,995		(37	)		249,844
Mortgage-backed securities: GSE residential		479,470		12,038		(160	)		491,348
Other securities		10,740		252		(13	)		10,979
Total available-for-sale	$	855,163	$	25,075	$	(998	)	$	879,240
Held-to-maturity:
U.S. Treasury securities and obligations of U.S government corporations and agencies	$	5,016	$	103	$	—		$	5,119

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, 2021 and 2020 (in thousands):

	Three months September 30,					Nine months September 30,
	2021		2020			2021		2020
Gross gains	$	11	$	116		$	88	$	934
Gross losses		—		(21	)		—		(21	)

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, 2021 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	$	116,855		$	63,561		$	11,268		$	—		$	191,684
Obligations of state and political subdivisions		24,335			82,566			224,078			7,765			338,744
Mortgage-backed securities: GSE residential		17,950			410,157			354,508			—			782,615
Other securities		6,055			24,860			3,008			—			33,923
Total available-for-sale investments	$	165,195		$	581,144		$	592,862		$	7,765		$	1,346,966
Weighted average yield		1.61	%		1.95	%		1.68	%		2.43	%		1.79	%
Full tax-equivalent yield		1.78	%		2.10	%		1.94	%		3.16	%		2.00	%
Held to maturity:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	5,004		$	—		$	—		$	—		$	5,004
Other securities		—									2,022			2,022
Total held-to-maturity	$	5,004		$	—		$	—		$	2,022		$	7,026
Weighted average yield		2.06	%		—	%		—	%		—	%		2.06	%
Full tax-equivalent yield		2.06	%		—	%		—	%		—	%		2.06	%

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, 2021 and December 31, 2020 (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, 2021
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	145,432	$	(2,435	)	$	9,649	$	(351	)	$	155,081	$	(2,786	)
Obligations of states and political subdivisions		87,767		(960	)		—		—			87,767		(960	)
Mortgage-backed securities: GSE residential		508,332		(7,084	)		93		(1	)		508,425		(7,085	)
Other securities		11,057		(36	)		—		—			11,057		(36	)
Total	$	752,588	$	(10,515	)	$	9,742	$	(352	)	$	762,330	$	(10,867	)
December 31, 2020
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	59,211	$	(788	)	$	—	$	—		$	59,211	$	(788	)
Obligations of states and political subdivisions		5,380		(37	)		—		—			5,380		(37	)
Mortgage-backed securities: GSE residential		57,609		(160	)		2,377		—			59,986		(160	)
Other securities		3,977		(13	)		—		—			3,977		(13	)
Total	$	126,177	$	(998	)	$	2,377	$	—		$	128,554	$	(998	)