Fair Value Measurement and Fair Value of Financial Instruments - Fair Value Measurement of Assets and Liabilities (Detail) (Recurring [Member], USD $)	Sep. 30, 2013	Dec. 31, 2012
Assets
Cash and cash equivalents	$ 2,518,377	$ 3,307,822
Total Assets	2,518,377	3,307,822
Liabilities
Contingent consideration	2,868,734	4,759,257
Debt discount	(99,682)	(129,587)
Total Liabilities	2,769,052	4,629,670
Level 1 [Member]
Assets
Cash and cash equivalents	2,518,377	3,307,822
Total Assets	2,518,377	3,307,822
Liabilities
Contingent consideration
Debt discount
Total Liabilities
Level 2 [Member]
Assets
Cash and cash equivalents
Total Assets
Liabilities
Contingent consideration
Debt discount	(99,682)	(129,587)
Total Liabilities	(99,682)	(129,587)
Level 3 [Member]
Assets
Cash and cash equivalents
Total Assets
Liabilities
Contingent consideration	2,868,734	4,759,257
Debt discount
Total Liabilities	$ 2,868,734	$ 4,759,257