Industry and Geographic Information - Consolidated Net Product Revenues by Disease State (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenues	$ 182,615	$ 175,410	$ 155,741
Infectious Disease [Member]
Segment Reporting Information [Line Items]
Revenues	130,416	128,079	110,982
Women's Health [Member]
Segment Reporting Information [Line Items]
Revenues	34,332	33,328	32,653
Gastrointestinal Disease [Member]
Segment Reporting Information [Line Items]
Revenues	7,414	6,622	6,328
Royalty, License Fees and Grant Revenue [Member]
Segment Reporting Information [Line Items]
Revenues	7,681	3,917	2,452
Other Disease [Member]
Segment Reporting Information [Line Items]
Revenues	$ 2,772	$ 3,464	$ 3,326