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Earnings Per Share - Reconciliation (Details) - USD ($)		3 Months Ended					9 Months Ended		12 Months Ended	15 Months Ended
Earnings Per Share - Reconciliation (Details) - USD ($)	Jan. 16, 2019	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018	Dec. 31, 2016	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2009	Mar. 31, 2019	Jan. 16, 2009
Basic earnings per share:
Weighted-average common shares outstanding		29,899,063		29,747,078			29,880,511	29,718,191
Net income		$ 12,173,000		$ 9,642,000			$ 29,919,000	$ 25,392,000
Basic earnings per share (in dollars per share)		$ 0.41		$ 0.32			$ 1.00	$ 0.85
Diluted earnings per share:
Weighted-average common shares outstanding		29,899,063		29,747,078			29,880,511	29,718,191
Diluted average common shares outstanding		30,438,333		30,383,891			30,390,965	30,297,294
Net earnings available to common stockholders		$ 12,173,000		$ 9,642,000			$ 29,919,000	$ 25,392,000
Diluted earnings per share (in dollars per share)		$ 0.40		$ 0.32			$ 0.98	$ 0.84
Warrants, exercise price (in dollars per share)	$ 14.23			$ 13.43				$ 13.43
Warrant term						10 years
Stock warrants exercised	$ (313,000)
Stock warrants exercised (in shares)	45,836
Warrant [Member]
Diluted earnings per share:
Antidilutive securities								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 [Member]
Diluted earnings per share:
Dilutive effect of share-based payment awards (in shares)		539,270		563,781			510,454	525,627
Employee and Nonemployee Stock Options [Member]
Diluted earnings per share:
Dilutive effect of share-based payment awards (in shares)				73,032				53,476