Schedule of Other Income Expense Net (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Component of Other Expense, Nonoperating [Line Items]
Unrealized loss on change in fair value of warrant liability	$ (6,577)		$ (2,785)
Reversal of interest expense and penalties on unrecognized tax liability		(10)		1,753
Foreign exchange	139		(118)
Other non-operating income (expenses)	30	(2)	8	(15)
Total other (expense) income, net	$ (6,408)	$ (12)	$ (2,895)	$ 1,738