Investments (Tables)

3 Months Ended

Mar. 31, 2022

Investments [Abstract]

Debt Securities, Available-for-sale

	March 31, 2022								December 31, 2021
	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	$	264,592	$	1,904	$	11,489	$	255,007	$	263,809	$	8,622	$	215	$	272,216
Mortgage-backed securities:
U.S. government agencies	1,158,996		2,092		45,995		1,115,093		1,080,381		18,739		4,809		1,094,311
Private label	8,368		95		—		8,463		8,555		553		—		9,108
Trust preferred securities	4,574		—		274		4,300		4,570		—		367		4,203
Corporate securities	27,247		206		803		26,650		27,292		1,047		12		28,327
Total Securities Available-for-Sale	$	1,463,777	$	4,297	$	58,561	$	1,409,513	$	1,384,607	$	28,961	$	5,403	$	1,408,165

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, 2022
	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	$	166,363	$	11,280	$	3,247	$	209	$	169,610	$	11,489
Mortgage-backed securities:
U.S. Government agencies	819,437		45,995		—		—		819,437		45,995
Trust preferred securities	—		—		4,300		274		4,300		274
Corporate securities	14,944		803		—		—		14,944		803
Total available-for-sale	$	1,000,744	$	58,078	$	7,547	$	483	$	1,008,291	$	58,561

	December 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	$	13,277	$	152	$	2,420	$	63	$	15,697	$	215
Mortgage-backed securities:
U.S. Government agencies	521,407		4,802		23,295		7		544,702		4,809
Trust preferred securities	—		—		4,203		367		4,203		367
Corporate securities	988		12		—		—		988		12
Total available-for-sale	$	535,672	$	4,966	$	29,918	$	437	$	565,590	$	5,403

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, 2022, 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	$	3,116	$	3,146
Due after one year through five years	45,143		45,506
Due after five years through ten years	396,831		391,126
Due after ten years	1,018,687		969,735
Total	$	1,463,777	$	1,409,513

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,
	2022		2021
Gross realized gains on securities sold	$	—	$	283
Gross realized losses on securities sold	—		—
Net investment security gains	$	—	$	283
Gross unrealized gains recognized on equity securities still held	$	7	$	—
Gross unrealized losses recognized on equity securities still held	(730)		(51)
Net unrealized losses recognized on equity securities still held	$	(723)	$	(51)