Reconciliation of Basic and Diluted Shares Amounts (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Net income	$ 5,029	$ 1,155	$ 3,872	$ 1,625	$ 265	$ 2,538	$ 3,613	$ 2,929	$ 11,681	$ 9,345	$ 8,170
Denominator:
Basic weighted average common shares outstanding	33,833,000	33,779,000	33,649,000	33,025,000	32,946,000	32,925,000	32,870,000	32,755,000	33,572,883	32,881,940	32,497,657
Weighted average common stock equivalents from assumed exercise of stock options and restricted stock awards									526,015	695,151	766,010
Diluted weighted average common shares outstanding	34,369,000	34,313,000	34,175,000	33,494,000	33,577,000	33,690,000	33,671,000	33,451,000	34,098,898	33,577,091	33,263,667
Basic net income per common share	$ 0.15	$ 0.03	$ 0.12	$ 0.05	$ 0.01	$ 0.08	$ 0.11	$ 0.09	$ 0.35	$ 0.28	$ 0.25
Diluted net income per common share	$ 0.15	$ 0.03	$ 0.11	$ 0.05	$ 0.01	$ 0.08	$ 0.11	$ 0.09	$ 0.34	$ 0.28	$ 0.25