Reconciliation of Basic and Diluted Shares Amounts (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerator:
Net income	$ (398,000)	$ 1,466,000	$ 2,825,000	$ 4,277,000	$ 3,328,000	$ 5,888,000	$ 4,539,000	$ 2,338,000	$ 8,170,214	$ 16,093,155	$ 14,156,037
Denominator:
Basic weighted average common shares outstanding	32,747,000	32,677,000	32,234,000	31,963,000	31,916,000	31,858,000	31,644,000	31,241,000	32,497,657	31,667,015	30,914,424
Weighted average common stock equivalents from assumed exercise of stock options and restricted stock awards									766,010	739,626	339,010
Diluted weighted average common shares outstanding	32,747,000	33,327,000	33,076,000	31,855,000	32,708,000	32,552,000	32,317,000	31,855,000	33,263,667	32,406,641	31,253,434
Basic net income per common share	$ (0.01)	$ 0.04	$ 0.09	$ 0.13	$ 0.10	$ 0.18	$ 0.14	$ 0.07	$ 0.25	$ 0.51	$ 0.46
Diluted net income per common share	$ (0.01)	$ 0.04	$ 0.09	$ 0.13	$ 0.10	$ 0.18	$ 0.14	$ 0.07	$ 0.25	$ 0.50	$ 0.45