Organization, Basis of Presentation and Summary of Significant Policies - Additional Information (Detail)	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($) Customer $ / shares	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) $ / shares
Basis Of Presentation [Line Items]
Common Stock, par value | $ / shares	$ 0.001		$ 0.001
Inventory allowances recorded	$ 200,000		$ 0
Product sales	$ 7,795,000	$ 2,102,000
Sales return maximum duration	18 months
Offered period for sales return prior to expiration	6 months
Offered period for sales return subsequent to expiration	12 months
Discount for prompt payment	2.00%
Number of large wholesalers | Customer	3
Percentage of accruals accounted by three large wholesalers	92.00%
Belbuca [Member]
Basis Of Presentation [Line Items]
Product sales			$ 0
Endo Agreement [Member]
Basis Of Presentation [Line Items]
Termination agreement date	Dec. 07, 2016
License termination effective date	Jan. 06, 2017
Minimum [Member]
Basis Of Presentation [Line Items]
Period of payments from customers	30 days
Accrual to payment cycle period	1 month
Maximum [Member]
Basis Of Presentation [Line Items]
Period of payments from customers	37 days
Accrual to payment cycle period	3 months