Quarterly Financial Data (Unaudited) - Summarized quarterly financial data (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Interim Reporting [Line Items]
Net revenues	$ 56,524	$ 53,380	$ 52,496	$ 42,849	$ 36,561	$ 36,942	$ 37,066	$ 31,722	$ 205,249	$ 142,291	$ 95,875
Gross Profit	10,322	10,810	10,756	8,576	7,489	7,824	7,478	6,459	40,464	29,250	23,334
Net income (loss)	$ 2,014	$ 2,504	$ 2,308	$ 1,251	$ 289	$ 1,020	$ 1,029	$ 442	$ 8,077	$ 2,780	$ 2,109
Earnings (loss) per Share, Basic	$ 0.16	$ 0.21	$ 0.20	$ 0.11	$ 0.03	$ 0.09	$ 0.09	$ 0.04	$ 0.68	$ 0.24	$ 0.19
Earnings (loss) per Share, Diluted	$ 0.16	$ 0.21	$ 0.20	$ 0.11	$ 0.03	$ 0.09	$ 0.09	$ 0.04	$ 0.68	$ 0.24	$ 0.19
Shares outstanding, Basic	12,256,237	12,140,674	11,713,206	11,683,306	11,545,768	11,409,533	11,409,533	11,402,821	11,948,356	11,441,914	11,362,361
Shares outstanding, Diluted	12,266,867	12,148,776	11,729,360	11,684,829	11,555,764	11,454,012	11,601,180	11,581,676	11,957,458	11,548,158	11,380,966