Schedule of Other Income Expense Net (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Component of Other Expense, Nonoperating [Line Items]
Unrealized gain on change in valuation of warrant liability	$ 745
Foreign currency transactions	(219)	16
Other non-operating expenses	(20)	(16)
Total other income, net	$ 506