Earnings per Common Share - Computation of Basic and Diluted Earnings per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Basic
Net Income	$ 3,596	$ 5,181	$ 8,231	$ 9,906
Preferred stock dividends	308	391	627	782
Net income available to common shareholders-basic	$ 3,288	$ 4,790	$ 7,604	$ 9,124
Weighted average common shares outstanding-basic	10,162,528	7,877,119	9,634,363	7,861,444
Basic earnings per common share	$ 0.32	$ 0.61	$ 0.79	$ 1.16
Diluted
Net income available to common shareholders-basic	$ 3,288	$ 4,790	$ 7,604	$ 9,124
Preferred stock dividends	308	391	627	782
Net income available to common shareholders-diluted	$ 3,596	$ 5,181	$ 8,231	$ 9,906
Weighted average common shares outstanding for basic earnings per common share	10,162,528	7,877,119	9,634,363	7,861,444
Add: Dilutive effects of convertible preferred shares	2,431,349	3,074,402	2,469,465	3,076,323
Average shares and dilutive potential common shares outstanding-diluted	12,593,877	10,951,521	12,103,828	10,937,767
Diluted earnings per common share	$ 0.29	$ 0.47	$ 0.68	$ 0.91