Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands, € in Millions	1 Months Ended			3 Months Ended	9 Months Ended
	Oct. 31, 2015 USD ($)	Feb. 28, 2015 USD ($)	Feb. 28, 2015 EUR (€)	Sep. 30, 2015 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2015 EUR (€)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2013 USD ($)
Description Of Business And Significant Accounting Policies [Line Items]
Allowance for doubtful accounts				$ 200	$ 200		$ 100
Cash and cash equivalents				46,355	46,355		70,933	$ 29,910	$ 71,639
VAT receivable				4,600	4,600		4,900
Reserve for excess, obsolete or unsalable inventory				713	713		0
Unrealized foreign exchange gain (loss) on intercompany balance				42	(1,832)
Intercompany foreign currency balance, amount				26,000	26,000	€ 23.3
Other Assets
Description Of Business And Significant Accounting Policies [Line Items]
VAT receivable, non-current				4,400	4,400		4,700
Prepaid Expenses and Other Current Assets
Description Of Business And Significant Accounting Policies [Line Items]
VAT receivable, current				200	$ 200		$ 200
Europe | Minimum
Description Of Business And Significant Accounting Policies [Line Items]
VAT receivable, collection period					3 months
Europe | Maximum
Description Of Business And Significant Accounting Policies [Line Items]
VAT receivable, collection period					5 years
ITALY
Description Of Business And Significant Accounting Policies [Line Items]
VAT receivable				$ 4,400	$ 4,400
ITALY | Minimum
Description Of Business And Significant Accounting Policies [Line Items]
VAT receivable, collection period					3 years
ITALY | Maximum
Description Of Business And Significant Accounting Policies [Line Items]
VAT receivable, collection period					5 years
Subsequent Event
Description Of Business And Significant Accounting Policies [Line Items]
Net proceeds in underwritten offering	$ 46,500
Aequus Biopharma, Inc | Affiliated Entity
Description Of Business And Significant Accounting Policies [Line Items]
Interest in majority-owned subsidiary				61.00%	61.00%	61.00%
Servier | Collaborative Arrangement Product Agreement | Up-front Payment Arrangement
Description Of Business And Significant Accounting Policies [Line Items]
Total consideration received		$ 1,700	€ 1.5