Investments (Tables)

3 Months Ended

Mar. 31, 2021

Investments [Abstract]

Aggregate Carrying And Approximate Market Values Of Available-For-Sale Securities

	March 31, 2021								December 31, 2020
	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	273,855		7,082		1,184		279,753		266,483		11,467		139		277,811
Mortgage-backed securities:
U.S. government agencies	834,608		24,328		3,382		855,554		815,682		34,807		105		850,384
Private label	9,691		705		—		10,396		9,976		916		—		10,892
Trust preferred securities	4,560		—		285		4,275		4,557		—		457		4,100
Corporate securities	32,421		857		3		33,275		31,465		2,146		1		33,610
Total Debt Securities	1,155,135		32,972		4,854		1,183,253		1,128,163		49,336		702		1,176,797
Certificates of deposit held for investment	1,992		—		—		1,992		1,992		—		—		1,992
Total Securities Available-for-Sale	$	1,157,127	$	32,972	$	4,854	$	1,185,245	$	1,130,155	$	49,336	$	702	$	1,178,789

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, 2021
	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	$	97,157	$	1,086	$	2,386	$	98	$	99,543	$	1,184
Mortgage-backed securities:
U.S. Government agencies	225,763		3,366		13,290		16		239,053		3,382
Trust preferred securities	—		—		4,275		285		4,275		285
Corporate securities	998		2		488		1		1,486		3
Total available-for-sale	$	323,918	$	4,454	$	20,439	$	400	$	344,357	$	4,854

	December 31, 2020
	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	$	10,578	$	139	$	—	$	—	$	10,578	$	139
Mortgage-backed securities:
U.S. Government agencies	62,412		105		35		—		62,447		105
Trust preferred securities	—		—		4,100		457		4,100		457
Corporate securities	488		1		—		—		488		1
Total available-for-sale	$	73,478	$	245	$	4,135	$	457	$	77,613	$	702

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, 2021, 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	$	16,063	$	4,470
Due after one year through five years	33,304		34,628
Due after five years through ten years	292,485		303,519
Due after ten years	813,283		840,636
Total	$	1,155,135	$	1,183,253

Gross Gains And Losses Realized

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,
	2021		2020
Gross realized gains on securities sold	$	283	$	134
Gross realized losses on securities sold	—		(71)
Net investment security gains	$	283	$	63
Gross unrealized gains recognized on equity securities still held	$	—	$	24
Gross unrealized losses recognized on equity securities still held	(51)		(2,426)
Net unrealized losses recognized on equity securities still held	$	(51)	$	(2,402)