Significant Customers and Concentrations of Risk - Summary of Significant Customers from which the Company Derived 10% or More of Total Revenue (Detail) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Concentration Risk [Line Items]
Total revenues		$ 13,478,763	$ 11,085,752	$ 38,025,925	$ 33,854,180
Teva [Member]
Concentration Risk [Line Items]
Total revenues		5,522,996	5,097,912	18,513,972	12,227,129
AMAG [Member]
Concentration Risk [Line Items]
Total revenues		2,369,950	362,775	3,275,832	362,775
McKesson [Member]
Concentration Risk [Line Items]
Total revenues	[1]	1,946,261	2,105,422	5,501,810	5,440,323
Ferring [Member]
Concentration Risk [Line Items]
Total revenues		1,246,300	$ 1,309,731	3,960,689	3,609,798
LEO Pharma [Member]
Concentration Risk [Line Items]
Total revenues		$ 0		$ 0	$ 6,000,000	[2]

[1] Represents estimated revenue based on OTREXUP™ shipments, a portion of which has not been recognized as revenue but is recorded in deferred revenue at the end of each period as discussed in Note 2 to the Consolidated Financial Statements.

[2] The licensing agreement with LEO Pharma A/S was terminated effective June 23, 2015 and accordingly no revenue was recognized or received from this customer for the three and nine months ended September 30, 2016.