Organization and Basis of Presentation - Additional Information (Detail)	3 Months Ended	9 Months Ended
	Sep. 30, 2015 USD ($) $ / shares	Sep. 30, 2015 USD ($) Product site $ / shares	Dec. 31, 2014 USD ($) $ / shares	Sep. 30, 2014 USD ($)
Basis Of Presentation [Line Items]
Common Stock, par value | $ / shares	$ 0.001	$ 0.001	$ 0.001
Inventory allowances recorded	$ 0	$ 0
Number of products | Product		1
Sales return maximum duration		18 months
Offered period for sales return prior to expiration		6 months
Offered period for sales return subsequent to expiration		12 months
Discount for prompt payment	2.00%	2.00%
Inventory write down	$ 300,000	$ 800,000
Number of contract manufacturing sites | site		2
Inventory valuation adjustments				$ 0
Bunavail [Member]
Basis Of Presentation [Line Items]
Deferred revenue related to sales	1,200,000	$ 1,200,000	$ 800,000
Deferred cost of sales	$ 1,100,000	$ 1,100,000	$ 700,000
Minimum [Member]
Basis Of Presentation [Line Items]
Period of payments from customers		30 days
Maximum [Member]
Basis Of Presentation [Line Items]
Period of payments from customers		37 days