Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Summary Of Significant Accounting Policies [Line Items]
Carrying value of investments	$ 12,009,000		$ 15,012,225
Fair value of investments	12,009,000		15,012,225
Inventory reserve	800,000		800,000
Product revenue	$ 10,841,047	$ 4,623,130
Cash discount to incentive for prompt payment	2.00%
OTREXUP [Member]
Summary Of Significant Accounting Policies [Line Items]
Product revenue	$ 3,309,774	$ 3,004,309
Deferred revenue balance	$ 834,234		$ 1,064,874