Net Sales By Product (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net product sales	$ 166,703	$ 156,471	$ 111,389
Net product sales
Segment Reporting Information [Line Items]
Net product sales	164,598	154,574	107,888
BELBUCA
Segment Reporting Information [Line Items]
Net product sales	148,189	136,128	97,538
Symproic
Segment Reporting Information [Line Items]
Net product sales	16,409	14,709	8,061
BUNAVAIL
Segment Reporting Information [Line Items]
Net product sales	$ 0	$ 3,737	$ 2,289
Revenue | Product Concentration Risk | BELBUCA
Segment Reporting Information [Line Items]
Concentration risk percentage	90.00%	88.10%	90.40%
Revenue | Product Concentration Risk | Symproic
Segment Reporting Information [Line Items]
Concentration risk percentage	10.00%	9.50%	7.50%
Revenue | Product Concentration Risk | BUNAVAIL
Segment Reporting Information [Line Items]
Concentration risk percentage	0.00%	2.40%	2.10%