Fair Values of Financial Instruments - Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets:
Cash and due from banks	$ 122,594	$ 167,146
Investment securities held to maturity	1,907,865	2,202,503
Loans held for sale	9,094	11,187
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash and due from banks	122,594	167,146
Interest-bearing deposits	126,061	474,154
Investment securities available for sale	2,459	999
Investment securities held to maturity	0	0
Loans held for sale	0	0
Loans	0	0
Federal Home Loan Bank stock	0	0
Derivative assets	0	0
Interest receivable	0	0
Liabilities at December 31:
Deposits	13,105,936	12,038,992
Borrowings:
Federal funds purchased	0
Securities sold under repurchase agreements	0	0
Federal Home Loan Bank advances	0	0
Subordinated debentures and other borrowings	0	0
Interest rate swap liability	0	0
Interest payable	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Cash and due from banks	0	0
Interest-bearing deposits	0	0
Investment securities available for sale	1,970,763	2,338,061
Investment securities held to maturity	1,893,271	2,188,600
Loans held for sale	9,094	11,187
Loans	0	0
Federal Home Loan Bank stock	38,525	28,736
Derivative assets	93,036	41,133
Interest receivable	85,070	57,187
Liabilities at December 31:
Deposits	1,251,017	690,089
Borrowings:
Federal funds purchased	171,560
Securities sold under repurchase agreements	167,396	181,572
Federal Home Loan Bank advances	615,211	337,005
Subordinated debentures and other borrowings	122,102	107,892
Interest rate swap liability	92,770	41,968
Interest payable	7,530	2,762
Significant Unobservable Inputs (Level 3)
Assets:
Cash and due from banks	0	0
Interest-bearing deposits	0	0
Investment securities available for sale	3,439	5,491
Investment securities held to maturity	14,594	13,903
Loans held for sale	0	0
Loans	11,156,217	9,068,319
Federal Home Loan Bank stock	0	0
Derivative assets	0	0
Interest receivable	0	0
Liabilities at December 31:
Deposits	0	0
Borrowings:
Federal funds purchased	0
Securities sold under repurchase agreements	0	0
Federal Home Loan Bank advances	0	0
Subordinated debentures and other borrowings	0	0
Interest rate swap liability	0	0
Interest payable	0	0
Carrying Amount
Assets:
Cash and due from banks	122,594	167,146
Interest-bearing deposits	126,061	474,154
Investment securities available for sale	1,976,661	2,344,551
Investment securities held to maturity	2,287,127	2,179,802
Loans held for sale	9,094	11,187
Loans	11,780,617	9,046,464
Federal Home Loan Bank stock	38,525	28,736
Derivative assets	93,036	41,133
Interest receivable	85,070	57,187
Liabilities at December 31:
Deposits	14,382,745	12,732,577
Borrowings:
Federal funds purchased	171,560
Securities sold under repurchase agreements	167,413	181,577
Federal Home Loan Bank advances	823,674	334,055
Subordinated debentures and other borrowings	151,298	118,618
Interest rate swap liability	92,770	41,968
Interest payable	$ 7,530	$ 2,762

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Amount 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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For banks and other depository institutions: Includes cash on hand (currency and coin), cash items in process of collection, noninterest bearing deposits due from other financial institutions (including corporate credit unions), and noninterest bearing balances with the Federal Reserve Banks, Federal Home Loan Banks and central banks.

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Fair value portion of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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Fair value portion of other liabilities.

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Fair value portion of securities that an entity sells and agrees to repurchase at a specified date for a specified price.

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