Quarterly Condensed Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Condensed Financial Information (Unaudited)
Interest income	$ 26,910	$ 26,006	$ 22,464	$ 19,007	$ 20,691	$ 19,827	$ 16,929	$ 15,492	$ 94,387	$ 72,939	$ 56,345
Interest expense	7,958	7,616	6,740	5,476	5,509	4,857	4,360	4,242	27,790	18,968	14,290
Net interest income	18,952	18,390	15,724	13,531	15,182	14,970	12,569	11,250	66,597	53,971	42,055
Provision for loan losses	1,400	592	240	240	240	240	240	240	2,472	960	960
Net Interest Income After Provision for Loan Losses	17,552	17,798	15,484	13,291	14,942	14,730	12,329	11,010	64,125	53,011	41,095
Noninterest income	14,907	8,056	16,626	8,091	6,924	11,629	6,658	3,293	47,680	28,504	27,008
Noninterest expense	10,800	8,942	8,261	6,641	7,384	7,173	6,376	5,787	34,644	26,720	20,922
Income Before Income Taxes	21,659	16,912	23,849	14,741	14,482	19,186	12,611	8,516	77,161	54,795	47,181
Income Tax Expense (Benefit)	1,330	6,445	9,091	5,611	5,728	7,587	4,986	3,367	22,477	21,668	18,798
Net Income	20,329	10,467	14,758	9,130	8,754	11,599	7,625	5,149	54,684	33,127	28,383
Less: preferred stock dividends	833	833	832	832	833	762	202	205	3,330	2,002	0
Net Income allocated to Common Shareholders	$ 19,496	$ 9,634	$ 13,926	$ 8,298	$ 7,921	$ 10,837	$ 7,423	$ 4,944	$ 51,354	$ 31,125	$ 28,383
Per common share data:
Basic earnings per share (in dollar per share)	$ 0.73	$ 0.45	$ 0.66	$ 0.39	$ 0.38	$ 0.51	$ 0.36	$ 0.23	$ 2.28	$ 1.47	$ 1.35
Diluted earnings per share (in dollar per share)	$ 0.73	$ 0.45	$ 0.66	$ 0.39	$ 0.38	$ 0.51	$ 0.36	$ 0.23	$ 2.28	$ 1.47	$ 1.35