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Earnings Per Share - Reconciliation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended	21 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2009	Sep. 30, 2018	Jan. 16, 2009
Basic earnings per share:
Weighted-average common shares outstanding	29,747,078	29,627,086		29,718,191	29,591,811
Net income	$ 9,642	$ 8,077		$ 25,392	$ 17,650
Net income available to common stockholders	$ 9,642	$ 8,077		$ 25,392	$ 17,650
Basic earnings per share (in dollars per share)	$ 0.32	$ 0.27		$ 0.85	$ 0.60
Diluted earnings per share:
Weighted-average common shares outstanding	29,747,078	29,627,086		29,718,191	29,591,811
Diluted average common shares outstanding	30,383,891	30,103,609		30,297,294	30,019,365
Net earnings available to common stockholders	$ 9,642	$ 8,077		$ 25,392	$ 17,650
Diluted earnings per share (in dollars per share)	$ 0.32	$ 0.27		$ 0.84	$ 0.59
Warrants, exercise price (in dollars per share)								$ 13.43
Warrant term			10 years
Antidilutive options and warrants
Diluted earnings per share:
One 10 year warrant		900,839			900,839
Warrants
Diluted earnings per share:
One 10 year warrant				815,339	815,339
Warrants, exercise price (in dollars per share)								$ 13.43
Warrant term				10 years	10 years	10 years	10 years
Restricted stock and restricted stock units
Diluted earnings per share:
Dilutive effect of share-based payment awards (in shares)	563,781	473,967		525,627	425,081
Stock options
Diluted earnings per share:
Dilutive effect of share-based payment awards (in shares)	73,032	2,556		53,476	2,473