Net Sales by Product (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Sales Information [Line Items]
Net product sales	$ 38,278	$ 19,769
BELBUCA
Sales Information [Line Items]
Net product sales	$ 33,469	$ 18,703
BELBUCA | Revenue Benchmark | Product Concentration Risk
Sales Information [Line Items]
Percent of net product sales	89.00%	95.00%
Symproic
Sales Information [Line Items]
Net product sales	$ 4,179	$ 0
Symproic | Revenue Benchmark | Product Concentration Risk
Sales Information [Line Items]
Percent of net product sales	11.00%	0.00%
BUNAVAIL
Sales Information [Line Items]
Net product sales	$ 67	$ 1,056
BUNAVAIL | Revenue Benchmark | Product Concentration Risk
Sales Information [Line Items]
Percent of net product sales	0.00%	5.00%
Product sales
Sales Information [Line Items]
Net product sales	$ 37,715	$ 19,759