Summarized Quarterly Financial Information (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Interest income	$ 42,499	$ 43,231	$ 44,312	$ 48,217	$ 48,548	$ 49,981	$ 50,238	$ 48,933	$ 178,259	$ 197,700	$ 163,901
Taxable equivalent adjustment	333	301	217	188	189	192	202	208
Interest income (FTE)	42,832	43,532	44,529	48,405	48,737	50,173	50,440	49,141
Interest expense	4,318	5,254	6,242	7,801	8,701	9,444	9,327	8,867	23,615	36,339	25,692
Net Interest Income	38,514	38,278	38,287	40,604	40,036	40,729	41,113	40,274
Financing Receivable, Credit Loss, Expense (Reversal)	474	1,026	1,250	7,972	(75)	274	(600)	(849)	10,722	(1,250)	(2,310)
Noninterest income	17,721	16,985	14,631	33,343	18,042	16,698	17,825	15,925	82,680	68,490	60,564
Noninterest expense	28,641	28,712	28,468	29,469	29,034	28,397	30,772	29,411	115,290	117,614	113,066
Income Loss From Continuing Operations Before Tax Equivalent Adjustment Income Taxes Extraordinary Items Noncontrolling Interest	27,120	25,525	23,200	36,506	29,119	28,756	28,766	27,637
Income tax expense	4,565	5,098	4,732	7,322	6,319	6,193	5,813	5,810	21,717	24,135	18,015
Interest Income Taxable Equivalent Adjustment - Tax	(333)	(301)	(217)	(188)	(189)	(192)	(202)	(208)
Net Income Available to Common Shareholders	22,222	20,126	18,251	28,996	22,611	22,371	22,751	21,619	89,595	89,352	70,002
Net earnings allocated to common shareholders	$ 21,992	$ 19,929	$ 18,051	$ 28,736	$ 22,372	$ 22,188	$ 22,553	$ 21,433	$ 88,708	$ 88,546	$ 69,348
Basic earnings per common share	$ 1.40	$ 1.25	$ 1.12	$ 1.79	$ 1.38	$ 1.36	$ 1.38	$ 1.31	$ 5.55	$ 5.43	$ 4.50
Diluted earnings per common share	$ 1.40	$ 1.25	$ 1.12	$ 1.78	$ 1.38	$ 1.36	$ 1.38	$ 1.30	$ 5.55	$ 5.42	$ 4.49
Basic	15,708	15,950	16,081	16,080	16,207	16,271	16,368	16,411	15,975	16,314	15,421
Average shares outstanding, diluted	15,733	15,970	16,097	16,101	16,230	16,289	16,386	16,429	15,995	16,333	15,439