Fair Value of Financial Instruments - Balances and Levels of Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financial assets:
Available-for-sale securities:	$ 1,419,360	$ 1,471,186
Equity securities, at fair value	3,031	2,990
Mortgage-backed securities - residential
Financial assets:
Available-for-sale securities:	979,400	1,034,193
Mortgage-backed securities - commercial
Financial assets:
Available-for-sale securities:	17,254	17,644
Municipal securities
Financial assets:
Available-for-sale securities:	267,097	264,420
U.S. Treasury securities
Financial assets:
Available-for-sale securities:	108,221	107,680
Corporate securities
Financial assets:
Available-for-sale securities:	6,859	7,187
Recurring Basis
Financial assets:
Equity securities, at fair value	3,031	2,990
Total securities	1,422,391	1,474,176
Total loans held for sale	78,906	113,240
Mortgage servicing rights	166,433	168,365
Derivatives	47,132	48,769
Financial liabilities:
Derivatives	54,544	63,229
Recurring Basis | U.S. government agency securities
Financial assets:
Available-for-sale securities:	40,529	40,062
Recurring Basis | Mortgage-backed securities - residential
Financial assets:
Available-for-sale securities:	979,400	1,034,193
Recurring Basis | Mortgage-backed securities - commercial
Financial assets:
Available-for-sale securities:	17,254	17,644
Recurring Basis | Municipal securities
Financial assets:
Available-for-sale securities:	267,097	264,420
Recurring Basis | U.S. Treasury securities
Financial assets:
Available-for-sale securities:	108,221	107,680
Recurring Basis | Corporate securities
Financial assets:
Available-for-sale securities:	6,859	7,187
Recurring Basis | Quoted prices in active markets for identical assets (liabilities) (level 1)
Financial assets:
Equity securities, at fair value	0	0
Total securities	0	0
Total loans held for sale	0	0
Mortgage servicing rights	0	0
Derivatives	0	0
Financial liabilities:
Derivatives	0	0
Recurring Basis | Quoted prices in active markets for identical assets (liabilities) (level 1) | U.S. government agency securities
Financial assets:
Available-for-sale securities:	0	0
Recurring Basis | Quoted prices in active markets for identical assets (liabilities) (level 1) | Mortgage-backed securities - residential
Financial assets:
Available-for-sale securities:	0	0
Recurring Basis | Quoted prices in active markets for identical assets (liabilities) (level 1) | Mortgage-backed securities - commercial
Financial assets:
Available-for-sale securities:	0	0
Recurring Basis | Quoted prices in active markets for identical assets (liabilities) (level 1) | Municipal securities
Financial assets:
Available-for-sale securities:	0	0
Recurring Basis | Quoted prices in active markets for identical assets (liabilities) (level 1) | U.S. Treasury securities
Financial assets:
Available-for-sale securities:	0	0
Recurring Basis | Quoted prices in active markets for identical assets (liabilities) (level 1) | Corporate securities
Financial assets:
Available-for-sale securities:	0	0
Recurring Basis | Significant other observable inputs (level 2)
Financial assets:
Equity securities, at fair value	3,031	2,990
Total securities	1,422,391	1,474,176
Total loans held for sale	69,639	82,750
Mortgage servicing rights	0	0
Derivatives	47,132	48,769
Financial liabilities:
Derivatives	54,544	63,229
Recurring Basis | Significant other observable inputs (level 2) | U.S. government agency securities
Financial assets:
Available-for-sale securities:	40,529	40,062
Recurring Basis | Significant other observable inputs (level 2) | Mortgage-backed securities - residential
Financial assets:
Available-for-sale securities:	979,400	1,034,193
Recurring Basis | Significant other observable inputs (level 2) | Mortgage-backed securities - commercial
Financial assets:
Available-for-sale securities:	17,254	17,644
Recurring Basis | Significant other observable inputs (level 2) | Municipal securities
Financial assets:
Available-for-sale securities:	267,097	264,420
Recurring Basis | Significant other observable inputs (level 2) | U.S. Treasury securities
Financial assets:
Available-for-sale securities:	108,221	107,680
Recurring Basis | Significant other observable inputs (level 2) | Corporate securities
Financial assets:
Available-for-sale securities:	6,859	7,187
Recurring Basis | Significant unobservable inputs (level 3)
Financial assets:
Equity securities, at fair value	0	0
Total securities	0	0
Total loans held for sale	9,267	30,490
Mortgage servicing rights	166,433	168,365
Derivatives	0	0
Financial liabilities:
Derivatives	0	0
Recurring Basis | Significant unobservable inputs (level 3) | U.S. government agency securities
Financial assets:
Available-for-sale securities:	0	0
Recurring Basis | Significant unobservable inputs (level 3) | Mortgage-backed securities - residential
Financial assets:
Available-for-sale securities:	0	0
Recurring Basis | Significant unobservable inputs (level 3) | Mortgage-backed securities - commercial
Financial assets:
Available-for-sale securities:	0	0
Recurring Basis | Significant unobservable inputs (level 3) | Municipal securities
Financial assets:
Available-for-sale securities:	0	0
Recurring Basis | Significant unobservable inputs (level 3) | U.S. Treasury securities
Financial assets:
Available-for-sale securities:	0	0
Recurring Basis | Significant unobservable inputs (level 3) | Corporate securities
Financial assets:
Available-for-sale securities:	0	0
Non-recurring Basis
Financial liabilities:
Total collateral dependent loans	929	2,860
Non-recurring Basis | Residential real estate | 1-to-4 family mortgage
Financial liabilities:
Total collateral dependent loans	389	366
Non-recurring Basis | Quoted prices in active markets for identical assets (liabilities) (level 1)
Financial liabilities:
Total collateral dependent loans	0	0
Non-recurring Basis | Quoted prices in active markets for identical assets (liabilities) (level 1) | Residential real estate | 1-to-4 family mortgage
Financial liabilities:
Total collateral dependent loans	0	0
Non-recurring Basis | Significant other observable inputs (level 2)
Financial liabilities:
Total collateral dependent loans	0	0
Non-recurring Basis | Significant other observable inputs (level 2) | Residential real estate | 1-to-4 family mortgage
Financial liabilities:
Total collateral dependent loans	0	0
Non-recurring Basis | Significant unobservable inputs (level 3)
Financial liabilities:
Total collateral dependent loans	929	2,860
Non-recurring Basis | Significant unobservable inputs (level 3) | Residential real estate | 1-to-4 family mortgage
Financial liabilities:
Total collateral dependent loans	$ 389	$ 366