EARNINGS PER SHARE - Computation of Basic and Diluted Earnings Per Common Share (Detail) - 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
Earnings per common share - basic
Net income allocated to common shareholders									$ 8,092	$ 7,880	$ 7,073
Weighted-average basic shares outstanding (in shares)									8,399,584	7,107,187	7,214,045
Basic earnings per share (in dollars per share)	$ 0.25	$ 0.24	$ 0.22	$ 0.26	$ 0.26	$ 0.29	$ 0.28	$ 0.28	$ 0.96	$ 1.11	$ 0.98
Earnings per common share - diluted
Dilutive effect of securities (in shares)									57,344	42,647	43,963
Total weighted average diluted shares outstanding (in shares)									8,456,928.00	7,149,834.00	7,258,008.00
Diluted earnings per share (in dollars per share)	$ 0.25	$ 0.24	$ 0.22	$ 0.26	$ 0.26	$ 0.29	$ 0.28	$ 0.28	$ 0.96	$ 1.10	$ 0.97