Consolidated Balance Sheet Details - Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Balance Sheet Related Disclosures [Abstract]
Accrued product returns	$ 4,694	$ 5,445
Liability for product transition for new formulation	3,041	0
Non-cancellable inventory purchase commitments for existing formulation	2,594	0
Accrued discounts and allowances	1,274	4,239
Accrued interest expense, current portion	0	3,033
Accrued clinical trial costs	1,785	1,238
Accrued sales and marketing costs	318	1,161
Astellas tail payment, current portion	0	1,131
Other accrued expenses	1,780	2,618
Accrued expenses	$ 15,486	$ 18,865