Description of Business and Summary of Significant Accounting Policies (Detail) € in Millions, shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) shares	Sep. 30, 2015 USD ($) shares	Sep. 30, 2016 USD ($) shares	Sep. 30, 2015 USD ($) shares	Sep. 30, 2016 EUR (€)	Sep. 30, 2016 USD ($)	Dec. 31, 2015 EUR (€)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Description Of Business And Significant Accounting Policies [Line Items]
Allowance for doubtful accounts						$ 0		$ 0
Allowance for doubtful accounts from collaborative arrangements						1,700,000.0		0
Accumulated deficit						2,143,954,000		2,098,317,000
Cash and cash equivalents		$ 46,355,000		$ 46,355,000		61,595,000		128,182,000	$ 70,933,000
VAT receivable						4,500,000		4,700,000
Reserve for excess, obsolete or unsalable inventory						981,000		1,265,000
Unrealized foreign exchange gain (loss) on intercompany balance	$ 484,000	$ 42,000	$ 1,024,000	$ (1,832,000)
Intercompany foreign currency balance, amount					€ 28.0	31,400,000	€ 27.2	29,500,000
Anti-dilutive securities excluded from computation of earnings per share amount (in shares) | shares	27.7	14.9	26.7	14.9
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						4,400,000
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
Other Assets
Description Of Business And Significant Accounting Policies [Line Items]
VAT receivable, non-current						4,400,000		4,200,000
Prepaid Expenses and Other Current Assets
Description Of Business And Significant Accounting Policies [Line Items]
VAT receivable, current						$ 100,000		$ 500,000
Aequus Biopharma, Inc | Affiliated Entity
Description Of Business And Significant Accounting Policies [Line Items]
Interest in majority-owned subsidiary					60.00%	60.00%