Industry and Geographic Information - Consolidated Net Product Revenues by Disease State (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 196,129	$ 184,158	$ 177,325
Infectious Disease [Member]
Segment Reporting Information [Line Items]
Revenues	141,857	130,416	128,079
Women's Health [Member]
Segment Reporting Information [Line Items]
Revenues	37,161	34,332	33,328
Gastrointestinal Disease [Member]
Segment Reporting Information [Line Items]
Revenues	7,224	7,414	6,622
Royalty, License Fees and Grant Revenue [Member]
Segment Reporting Information [Line Items]
Revenues	6,189	7,681	3,917
Other Disease [Member]
Segment Reporting Information [Line Items]
Revenues	$ 3,698	$ 4,315	$ 5,379