Business Combination and BELBUCA Acquisition - Additional Information (Detail) - USD ($)		12 Months Ended
	Jan. 06, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Income tax benefit		$ 15,972,000	$ 0	$ 0
Bargain purchase gain		$ 27,336,000
BELBUCA [Member]
Business Acquisition [Line Items]
Useful life of equipment		7 years
Deferred tax liability	$ (15,972,000)
Income tax benefit		$ 16,000,000
Bargain purchase gain	$ 27,336,000	$ 27,300,000
BELBUCA [Member] | License and Distribution Rights [Member]
Business Acquisition [Line Items]
Amortization of intangible asset		10 years
Endo Agreement [Member]
Business Acquisition [Line Items]
Termination agreement date		Dec. 07, 2016
License termination effective date		Jan. 06, 2017
Potential milestone payments on intellectual property rights		$ 5,000,000
Term of Endo Agreement		2 years
Contract termination claims, description		Together with the Asset Purchase Price, pursuant to the terms of the Termination Agreement, the Company will also pay to Endo a fee in the amount of $5 million in consideration for (i) Endo's agreement not to compete for a period of two years from the closing date of the termination agreement and (ii) Endo's waiver of its right to sell product for twelve months following the closing of the termination agreement.