Other Intangible Assets - Summary of Other Intangible Assets Net Consisting of Product Rights and Licenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 52,950	$ 52,950
Accumulated Amortization	(16,247)	(11,090)
Intangible Assets, net	36,703	41,860
Product Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	6,050	6,050
Accumulated Amortization	(5,442)	(4,881)
Intangible Assets, net	608	1,169
License and Distribution Rights [Member] | BELBUCA [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	45,000	45,000
Accumulated Amortization	(9,000)	(4,500)
Intangible Assets, net	36,000	40,500
Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	1,900	1,900
Accumulated Amortization	(1,805)	(1,709)
Intangible Assets, net	$ 95	$ 191
Weighted average Useful Life	15 years
Weighted Average [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average Useful Life	9 years 2 months 23 days	10 years 3 months
Weighted Average [Member] | Product Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average Useful Life	1 year 29 days	1 year 2 months 15 days
Weighted Average [Member] | License and Distribution Rights [Member] | BELBUCA [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average Useful Life	7 years 7 months 24 days	8 years 6 months
Weighted Average [Member] | Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average Useful Life	6 months	6 months 14 days