Fair Value Measurements (Estimated Fair Values of Financial Assets and Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financial assets, Estimated Fair Value
Investment securities held to maturity	$ 125,076	$ 65,828
Fair Value, Inputs, Level 1 [Member] | Carrying Amount [Member]
Financial assets, Estimated Fair Value
Cash and cash equivalents	227,086	186,917
Fair Value, Inputs, Level 1 [Member] | Estimated Fair Value [Member]
Financial assets, Estimated Fair Value
Cash and cash equivalents	227,086	186,917
Fair Value, Inputs, Level 2 [Member] | Carrying Amount [Member]
Financial assets, Estimated Fair Value
Investment securities held to maturity	125,929	65,706
Restricted securities	3,189	3,626
Cash surrender value on life insurance	41,343	31,018
Financial liabilities, Estimated Fair Value
Noninterest-bearing demand	533,823	509,091
Checking plus interest	405,601	446,243
Money market	381,461	292,974
Savings	202,198	177,524
Club	782	392
Certificates of deposit, $100,000 or more	133,378	129,623
Other time	143,393	144,858
Securities sold under retail repurchase agreement	3,501	1,050
Subordinated debt	24,460	24,429
Fair Value, Inputs, Level 2 [Member] | Estimated Fair Value [Member]
Financial assets, Estimated Fair Value
Investment securities held to maturity	125,076	65,828
Restricted securities	3,189	3,626
Cash surrender value on life insurance	41,343	31,018
Financial liabilities, Estimated Fair Value
Noninterest-bearing demand	533,823	509,091
Checking plus interest	405,601	446,243
Money market	381,461	292,974
Savings	202,198	177,524
Club	782	392
Certificates of deposit, $100,000 or more	135,376	131,271
Other time	144,917	146,137
Securities sold under retail repurchase agreement	3,501	1,050
Subordinated debt	24,869	25,745
Fair Value, Inputs, Level 3 [Member] | Carrying Amount [Member]
Financial assets, Estimated Fair Value
Loans, net	1,447,209	1,440,368
Fair Value, Inputs, Level 3 [Member] | Estimated Fair Value [Member]
Financial assets, Estimated Fair Value
Loans, net	$ 1,447,025	$ 1,436,292