Securities - Schedule of Securities Available-for-Sale (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,072,913,000	$ 1,869,198,000
Gross Unrealized Gains	6,699,000	36,068,000
Gross Unrealized Losses	(155,992,000)	(15,649,000)
Allowance for Credit Losses	0	0
Fair Value	1,923,620,000	1,889,617,000
Obligations of State and Political Subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	951,417,000	896,048,000
Gross Unrealized Gains	6,248,000	31,138,000
Gross Unrealized Losses	(77,796,000)	(1,480,000)
Allowance for Credit Losses	0	0
Fair Value	879,869,000	925,706,000
MBS/CMO
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	890,290,000	797,693,000
Gross Unrealized Gains	451,000	4,738,000
Gross Unrealized Losses	(62,437,000)	(10,481,000)
Allowance for Credit Losses	0	0
Fair Value	828,304,000	791,950,000
US Gov’t Sponsored Entities & Agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	231,206,000	175,457,000
Gross Unrealized Gains	0	192,000
Gross Unrealized Losses	(15,759,000)	(3,688,000)
Allowance for Credit Losses	0	0
Fair Value	$ 215,447,000	$ 171,961,000

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
-Section 45
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Amortized cost excluding accrued interest, before allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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