Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net income	$ 17,136	$ 16,682	$ 14,688	$ 15,286	$ (6,200)	$ 10,739	$ 9,433	$ 9,044	$ 63,792	$ 23,016	$ 36,036
Denominator for basic earnings per share – Weighted average shares outstanding (in shares)									20,234,792	17,150,125	16,859,623
Effect of dilutive potential common shares (in shares)									155,375	248,798	168,499
Adjusted weighted-average diluted shares (in shares)									20,390,167	17,398,923	17,028,122
Basic earnings per share (in dollars per share)	$ 0.85	$ 0.82	$ 0.73	$ 0.76	$ (0.35)	$ 0.63	$ 0.56	$ 0.53	$ 3.15	$ 1.34	$ 2.14
Diluted earnings per share (in dollars per share)	$ 0.84	$ 0.82	$ 0.72	$ 0.75	$ (0.35)	$ 0.62	$ 0.55	$ 0.53	$ 3.13	$ 1.32	$ 2.12
Antidilutive shares excluded from computation of average dilutive earnings per share (in shares)									19,422	27,159	0