Estimated Amortization Expense in Future Years (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
2012	$ 682,391
2013	223,488
2014	81,882
Finite-Lived Intangible Assets, Future Amortization Expense, Total	$ 987,761