Components of Accounts Payable and Accrued Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Accounts Payable and Accrued Liabilities [Line Items]
Accounts payable	$ 775	$ 3,557
Accrued employee compensation and related taxes.	3,893	4,018
Accrued license fees	1,500
Accrued legal	891	518
Total	11,686	12,472
Research and Development Operations
Accounts Payable and Accrued Liabilities [Line Items]
Accrued liabilities	2,085	1,652
Sales Allowances
Accounts Payable and Accrued Liabilities [Line Items]
Accrued liabilities	1,530	1,052
Other Accrued Liabilities
Accounts Payable and Accrued Liabilities [Line Items]
Accrued liabilities	$ 1,012	$ 1,675