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Securities - Amortized Cost and Estimated Fair Value of Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Available for sale:
Amortized Cost	$ 1,280,854		$ 1,407,675
Gross Unrealized Gains	794		297
Gross Unrealized Losses	(120,683)		(154,341)
Fair Value	1,160,965		1,253,631
Allowance for Credit Losses	0		0
Net Carrying Amount	1,160,965		1,253,631
Held to maturity:
Amortized Cost	11,148
Fair Value	10,701		10,848
Allowance for Credit Losses	(52)	$ (57)	(63)	$ (890)	$ (935)	$ (899)
Net Carrying Amount	11,096		11,615
Securities carried at fair value through income:
Fair Value	6,533		6,808
State and municipal securities
Available for sale:
Amortized Cost	323,507		323,356
Gross Unrealized Gains	293		210
Gross Unrealized Losses	(34,938)		(41,440)
Fair Value	288,862		282,126
Allowance for Credit Losses	0		0
Net Carrying Amount	288,862		282,126
Held to maturity:
Amortized Cost	11,148		11,678
Gross Unrealized Gains	0		0
Gross Unrealized Losses	(447)		(830)
Fair Value	10,701		10,848
Allowance for Credit Losses	(52)		(63)
Net Carrying Amount	11,096		11,615
Securities carried at fair value through income:
Amortized Cost	6,515		6,815
Fair Value	6,533		6,808
Net Carrying Amount	6,533		6,808
Corporate bonds
Available for sale:
Amortized Cost	86,288		92,244
Gross Unrealized Gains	286		80
Gross Unrealized Losses	(6,306)		(8,689)
Fair Value	80,268		83,635
Allowance for Credit Losses	0		0
Net Carrying Amount	80,268		83,635
U.S. treasury and government agency securities
Available for sale:
Amortized Cost	48,710		84,377
Gross Unrealized Gains	5		3
Gross Unrealized Losses	(3,328)		(4,740)
Fair Value	45,387		79,640
Allowance for Credit Losses	0		0
Net Carrying Amount	45,387		79,640
Commercial mortgage-backed securities
Available for sale:
Amortized Cost	108,079		104,459
Gross Unrealized Gains	30		0
Gross Unrealized Losses	(7,937)		(11,063)
Fair Value	100,172		93,396
Allowance for Credit Losses	0		0
Net Carrying Amount	100,172		93,396
Residential mortgage-backed securities
Available for sale:
Amortized Cost	523,289		569,622
Gross Unrealized Gains	6		0
Gross Unrealized Losses	(48,126)		(63,120)
Fair Value	475,169		506,502
Allowance for Credit Losses	0		0
Net Carrying Amount	475,169		506,502
Commercial collateralized mortgage obligations
Available for sale:
Amortized Cost	51,401		39,386
Gross Unrealized Gains	174		0
Gross Unrealized Losses	(3,065)		(4,203)
Fair Value	48,510		35,183
Allowance for Credit Losses	0		0
Net Carrying Amount	48,510		35,183
Residential collateralized mortgage obligations
Available for sale:
Amortized Cost	139,580		150,710
Gross Unrealized Gains	0		0
Gross Unrealized Losses	(16,983)		(20,566)
Fair Value	122,597		130,144
Allowance for Credit Losses	0		0
Net Carrying Amount	$ 122,597		130,144
Asset-backed securities
Available for sale:
Amortized Cost			43,521
Gross Unrealized Gains			4
Gross Unrealized Losses			(520)
Fair Value			43,005
Allowance for Credit Losses			0
Net Carrying Amount			$ 43,005

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