Accrued Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accrued Liabilities [Line Items]
Accrued compensation and related liabilities	$ 7,503	$ 6,481
Accrued professional fees	474	1,864
Accrued contract manufacturing expense		162
Other accrued liabilities	1,343	781
Total accrued liabilities	$ 9,320	$ 9,288