Fair Value of Financial Instruments - Carrying Values and Estimated Fair Values (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Financial Assets:
Cash and cash equivalents	$ 332,771	$ 263,893
Certificates of deposit with banks	11,803	11,803
Investment securities available-for-sale	450,772	410,624
Equity securities	32,215	27,585
Bank-owned life insurance	41,762	41,262
Financial Liabilities:
FHLB and other borrowings	100	0
Carrying Value
Financial Assets:
Cash and cash equivalents	332,771	263,893
Certificates of deposit with banks	11,803	11,803
Investment securities available-for-sale	450,772	410,624
Equity securities	32,215	27,585
Loans held-for-sale		1,062
Loans receivable, net	1,672,444	1,427,900
Mortgage servicing rights	2,759	2,942
Accrued interest receivable	8,312	7,793
Bank-owned life insurance	41,762	41,262
Financial Liabilities:
Deposits	2,229,175	1,982,389
Repurchase agreements	11,361	10,266
FHLB and other borrowings	100
Accrued interest payable	517	572
Subordinated debt	43,480	43,407
Estimated Fair Value
Financial Assets:
Cash and cash equivalents	332,771	263,893
Certificates of deposit with banks	11,943	11,986
Investment securities available-for-sale	450,772	410,624
Equity securities	32,215	27,585
Loans held-for-sale		1,062
Loans receivable, net	1,684,871	1,434,275
Mortgage servicing rights	2,759	2,942
Accrued interest receivable	8,312	7,793
Bank-owned life insurance	41,762	41,262
Financial Liabilities:
Deposits	2,186,598	1,964,860
Repurchase agreements	11,361	10,266
FHLB and other borrowings	100
Accrued interest payable	517	572
Subordinated debt	45,837	45,536
Interest rate swap | Carrying Value
Financial Assets:
Derivative asset	9,447	13,822
Financial Liabilities:
Derivative liability	9,447	13,822
Interest rate swap | Estimated Fair Value
Financial Assets:
Derivative asset	9,447	13,822
Financial Liabilities:
Derivative liability	9,447	13,822
Fair value hedge | Carrying Value
Financial Assets:
Derivative asset	1,942	2,215
Financial Liabilities:
Derivative liability	1,384	2,141
Fair value hedge | Estimated Fair Value
Financial Assets:
Derivative asset	1,942	2,215
Financial Liabilities:
Derivative liability	1,384	2,141
Quoted Prices in Active Markets for Identical Assets (Level I) | Estimated Fair Value
Financial Assets:
Cash and cash equivalents	332,771	263,893
Certificates of deposit with banks	0	0
Investment securities available-for-sale	0	0
Equity securities	447	472
Loans held-for-sale		0
Loans receivable, net	0	0
Mortgage servicing rights	0	0
Accrued interest receivable	0	0
Bank-owned life insurance	0	0
Financial Liabilities:
Deposits	0	0
Repurchase agreements	0	0
FHLB and other borrowings	0
Accrued interest payable	0	0
Subordinated debt	0	0
Quoted Prices in Active Markets for Identical Assets (Level I) | Interest rate swap | Estimated Fair Value
Financial Assets:
Derivative asset	0	0
Financial Liabilities:
Derivative liability	0	0
Quoted Prices in Active Markets for Identical Assets (Level I) | Fair value hedge | Estimated Fair Value
Financial Assets:
Derivative asset	0	0
Financial Liabilities:
Derivative liability	0	0
Significant Other Observable Inputs (Level II) | Estimated Fair Value
Financial Assets:
Cash and cash equivalents	0	0
Certificates of deposit with banks	11,943	11,986
Investment securities available-for-sale	411,002	366,945
Equity securities	0	0
Loans held-for-sale		1,062
Loans receivable, net	0	0
Mortgage servicing rights	0	0
Accrued interest receivable	2,413	2,770
Bank-owned life insurance	41,762	41,262
Financial Liabilities:
Deposits	2,186,598	1,964,860
Repurchase agreements	11,361	10,266
FHLB and other borrowings	100
Accrued interest payable	517	572
Subordinated debt	45,837	45,536
Significant Other Observable Inputs (Level II) | Interest rate swap | Estimated Fair Value
Financial Assets:
Derivative asset	9,447	13,822
Financial Liabilities:
Derivative liability	9,447	13,822
Significant Other Observable Inputs (Level II) | Fair value hedge | Estimated Fair Value
Financial Assets:
Derivative asset	1,942	2,215
Financial Liabilities:
Derivative liability	1,384	2,141
Significant Unobservable Inputs (Level III) | Estimated Fair Value
Financial Assets:
Cash and cash equivalents	0	0
Certificates of deposit with banks	0	0
Investment securities available-for-sale	39,770	43,679
Equity securities	31,768	27,113
Loans held-for-sale		0
Loans receivable, net	1,684,871	1,434,275
Mortgage servicing rights	2,759	2,942
Accrued interest receivable	5,899	5,023
Bank-owned life insurance	0	0
Financial Liabilities:
Deposits	0	0
Repurchase agreements	0	0
FHLB and other borrowings	0
Accrued interest payable	0	0
Subordinated debt	0	0
Significant Unobservable Inputs (Level III) | Interest rate swap | Estimated Fair Value
Financial Assets:
Derivative asset	0	0
Financial Liabilities:
Derivative liability	0	0
Significant Unobservable Inputs (Level III) | Fair value hedge | Estimated Fair Value
Financial Assets:
Derivative asset	0
Financial Liabilities:
Derivative liability	$ 0	$ 0