Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Payables And Accruals [Abstract]
Product sales reserves and allowances	$ 26,662	$ 9,998
Accrued compensation related expenses	6,879	7,169
Inventory received, not invoiced	2,405	5,398
Accrued income taxes		133
Accrued marketing and market research expenses	5,036	5,201
Accrued research and development expenses	812	864
Accrued interest on convertible notes	649	184
Accrued legal and professional expenses	1,347	984
Other accrued expenses	271	481
Accrued expenses	$ 44,061	$ 30,412