Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Schedule Of Intangible Assets [Line Items]
Total intangible assets, Gross Carrying Value	$ 38,865,584	$ 39,209,211
Intangible assets subject to amortization, Gross Carrying Value	996,616	963,340
Intangible assets subject to amortization, Accumulated Amortization	(516,395)	(486,941)
Intangible assets subject to amortization, Net Book Value	480,221	476,399
Total intangible assets, Net Book Value	38,349,189	38,722,270
IPR&D [Member]
Schedule Of Intangible Assets [Line Items]
Intangible assets, Net Book Value	37,868,968	38,245,871
Internally Developed Patents [Member]
Schedule Of Intangible Assets [Line Items]
Intangible assets subject to amortization, Gross Carrying Value	711,616	678,340
Intangible assets subject to amortization, Accumulated Amortization	(270,869)	(249,601)
Intangible assets subject to amortization, Net Book Value	$ 440,747	$ 428,739
Internally Developed Patents [Member] | Minimum [Member]
Schedule Of Intangible Assets [Line Items]
Estimated Useful Lives	6 years	6 years
Internally Developed Patents [Member] | Maximum [Member]
Schedule Of Intangible Assets [Line Items]
Estimated Useful Lives	10 years	10 years
Acquired Licenses [Member]
Schedule Of Intangible Assets [Line Items]
Intangible assets subject to amortization, Gross Carrying Value	$ 285,000	$ 285,000
Intangible assets subject to amortization, Accumulated Amortization	(245,526)	(237,340)
Intangible assets subject to amortization, Net Book Value	$ 39,474	$ 47,660
Acquired Licenses [Member] | Minimum [Member]
Schedule Of Intangible Assets [Line Items]
Estimated Useful Lives	16 years	16 years
Acquired Licenses [Member] | Maximum [Member]
Schedule Of Intangible Assets [Line Items]
Estimated Useful Lives	20 years	20 years