Schedule of Other Income Expense Net (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Component of Other Expense, Nonoperating [Line Items]
Unrealized gain (loss) on change in valuation of warrant liability	$ 2,347		$ (16,807)
Change in valuation of embedded derivatives	100
Reversal of interest expense and penalties on unrecognized tax liability settled		1,989
Reversal of accrued interest and penalty on state use tax audit		771
Foreign currency transactions	64	(9)
Other non-operating income (expenses)	203	77	(443)
Total other Income (expense), net	$ 2,714	$ 2,828	$ (17,250)