Investment Securities (Tables)

3 Months Ended

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

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
March 31, 2021
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations & agencies	$	174,789	$	377	$	(3,636	)	$	171,530
Obligations of states and political subdivisions		249,776		9,226		(1,283	)		257,719
Mortgage-backed securities: GSE residential		620,102		7,988		(6,138	)		621,952
Other securities		36,116		699		(68	)		36,747
Total available-for-sale	$	1,080,783	$	18,290	$	(11,125	)	$	1,087,948
Held-to-maturity:
U.S. Treasury securities and obligations of U.S. government corporations & agencies	$	5,012	$	80	$	—		$	5,092
Annuity		2,033		—		—			2,033
Total held-to-maturity	$	7,045	$	80	$	—		$	7,125
December 31, 2020
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations & 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 & 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 months ended March 31, 2021 and 2020 (in thousands):

	Three months March 31,
	2021		2020
Gross gains	$	4	$	531
Gross losses		—		—

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 March 31, 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	$	105,823		$	54,392		$	11,315		$	—		$	171,530
Obligations of state and political subdivisions		29,540			71,481			152,466			4,232			257,719
Mortgage-backed securities: GSE residential		26,948			293,661			301,343			—			621,952
Other securities		12,042			20,070			4,635			—			36,747
Total available-for-sale investments	$	174,353		$	439,604		$	469,759		$	4,232		$	1,087,948
Weighted average yield		1.87	%		2.28	%		1.69	%		2.57	%		1.96	%
Full tax-equivalent yield		2.06	%		2.45	%		1.94	%		3.52	%		2.17	%
Held to Maturity:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	5,012		$	—		$	—		$	—		$	5,012
Annuity		—									2,033			2,033
Total held-to-maturity	$	5,012		$	—		$	—		$	2,033		$	7,045
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 March 31, 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
March 31, 2021
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	144,404	$	(3,636	)	$	—	$	—		$	144,404	$	(3,636	)
Obligations of states and political subdivisions		51,381		(1,283	)		—		—			51,381		(1,283	)
Mortgage-backed securities: GSE residential		230,029		(5,155	)		129,370		(983	)		359,399		(6,138	)
Other securities		12,679		(68	)		—		—			12,679		(68	)
Total	$	438,493	$	(10,142	)	$	129,370	$	(983	)	$	567,863	$	(11,125	)
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	)