Fair Value of Financial Instruments - Estimated Fair Values and Carrying Values of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financial assets:
Loans, net	$ 7,884,927	$ 7,479,103
Interest receivable	39,069	38,528
Carrying amount
Financial assets:
Cash and cash equivalents	1,743,311	1,797,740
Investment securities	1,686,738	1,681,892
Loans, net	7,884,927	7,479,103
Loans held for sale	396,728	752,223
Interest receivable	39,069	38,528
Mortgage servicing rights	144,675	115,512
Derivatives	38,180	27,384
Financial liabilities:
Deposits, Without stated maturities	9,940,962	9,705,816
Deposits, With stated maturities	1,055,316	1,131,081
Securities sold under agreement to repurchase and federal funds sold	25,937	40,716
Subordinated debt	128,308	129,544
Interest payable	1,476	3,162
Derivatives	33,029	21,000
Fair Value
Financial assets:
Cash and cash equivalents	1,743,311	1,797,740
Investment securities	1,686,738	1,681,892
Loans, net	7,872,659	7,566,717
Loans held for sale	396,728	752,223
Interest receivable	39,069	38,528
Mortgage servicing rights	144,675	115,512
Derivatives	38,180	27,384
Financial liabilities:
Deposits, Without stated maturities	9,940,962	9,705,816
Deposits, With stated maturities	1,060,935	1,137,647
Securities sold under agreement to repurchase and federal funds sold	25,937	40,716
Subordinated debt	129,742	133,021
Interest payable	1,476	3,162
Derivatives	33,029	21,000
Fair Value \| Level 1
Financial assets:
Cash and cash equivalents	1,743,311	1,797,740
Investment securities	0	0
Loans, net	0	0
Loans held for sale	0	0
Interest receivable	101	36
Mortgage servicing rights	0	0
Derivatives	0	0
Financial liabilities:
Deposits, Without stated maturities	9,940,962	9,705,816
Deposits, With stated maturities	0	0
Securities sold under agreement to repurchase and federal funds sold	25,937	40,716
Subordinated debt	0	0
Interest payable	124	140
Derivatives	0	0
Fair Value \| Level 2
Financial assets:
Cash and cash equivalents	0	0
Investment securities	1,686,738	1,681,892
Loans, net	0	0
Loans held for sale	318,549	672,924
Interest receivable	6,806	6,461
Mortgage servicing rights	0	0
Derivatives	38,180	27,384
Financial liabilities:
Deposits, Without stated maturities	0	0
Deposits, With stated maturities	1,060,935	1,137,647
Securities sold under agreement to repurchase and federal funds sold	0	0
Subordinated debt	0	0
Interest payable	960	1,510
Derivatives	33,029	21,000
Fair Value \| Level 3
Financial assets:
Cash and cash equivalents	0	0
Investment securities	0	0
Loans, net	7,872,659	7,566,717
Loans held for sale	78,179	79,299
Interest receivable	32,162	32,031
Mortgage servicing rights	144,675	115,512
Derivatives	0	0
Financial liabilities:
Deposits, Without stated maturities	0	0
Deposits, With stated maturities	0	0
Securities sold under agreement to repurchase and federal funds sold	0	0
Subordinated debt	129,742	133,021
Interest payable	392	1,512
Derivatives	$ 0	$ 0

Deposits with stated maturities fair value disclosure.

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Deposits without stated maturities fair value disclosure.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Amount excluding accrued interest, after allowance for credit loss, of financing receivable.

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Amount of interest payable on debt, including, but not limited to, trade payables.

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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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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Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

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Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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