Investment in Inex Bio, Inc - Additional Information (Detail) - USD ($)		1 Months Ended			2 Months Ended	12 Months Ended
	Mar. 30, 2015	Apr. 30, 2015	May 31, 2012	Apr. 30, 2012	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2013
Asset Purchase [Line Items]
Number of shares acquired during period			57,000
Stock issued during period, value, acquisitions			$ 200,000
Outstanding shares acquired, percentage			22.20%
Percentage of fully diluted shares acquired			17.40%
Proceeds from exercise of warrants						$ 52,000	$ 7,348,000	$ 0
Stock-based compensation expense						73,852,000	211,221,000	789,000
Common Class A
Asset Purchase [Line Items]
Stock price of warrants										$ 2.44
Stock-based compensation expense								200,000
Inex Bio Holdings, LLC
Asset Purchase [Line Items]
Payments to acquire business						6,500,000
Stock price of warrants	$ 10.72
Term of warrants after closing date of the purchase agreement	15 days
Expected volatility rate	80.00%
Issuance of warrants in Inex Bio acquisition						22,747,000
Stock-based compensation expense						22,700,000
Cash based compensation						$ 5,400,000
Inex Bio Holdings, LLC | Common Class A
Asset Purchase [Line Items]
Warrants issued to acquire shares						2,609,520
Common stock exercise price						$ 2.00
Proceeds from exercise of warrants		$ 5,200,000
Other Owner Of Inex Bio Inc
Asset Purchase [Line Items]
Payments to acquire business	$ 1,500,000
Stock price of warrants	$ 10.72
Term of warrants after closing date of the purchase agreement	15 days
Expected volatility rate	80.00%
Issuance of warrants in Inex Bio acquisition						$ 5,170,000
Other Owner Of Inex Bio Inc | Common Class A
Asset Purchase [Line Items]
Warrants issued to acquire shares	593,072
Common stock exercise price	$ 2.00
Proceeds from exercise of warrants		$ 1,200,000
Inex Bio
Asset Purchase [Line Items]
Intangible assets amortizes period						4 years
Cambridge Equities, L.P | Inex Bio Holdings, LLC
Asset Purchase [Line Items]
Ownership percentage of third party business					50.00%
Eragon Ventures, LLC
Asset Purchase [Line Items]
Number of shares acquired during period					220,000
Ownership percentage of third party business					50.00%
Percentage shares acquired					67.30%
Payments to acquire business					$ 1,100,000
Inex license agreement
Asset Purchase [Line Items]
Milestone payment amount							$ 0	$ 0	$ 0
Percentage of royalty on net sales				5.00%
Up front fee | Inex license agreement
Asset Purchase [Line Items]
License fees received				$ 300,000
Maximum | Inex license agreement
Asset Purchase [Line Items]
Milestone payment amount				$ 800,000