Income Taxes - Additional Information (Detail) (USD $)			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Internal Revenue Service (IRS)	Dec. 31, 2012 State and Local Jurisdiction	Dec. 31, 2012 Federal
Income Taxes [Line Items]
Tax years open to examination			Our U.S. federal tax returns for 2010 and subsequent years remain open to examination.	Our California and Massachusetts tax returns for 2008 and subsequent years remain open to examination.
Accrued current taxes payable	$ (8,600,000)
Tax years under examination			In December 2012, the IRS concluded their examination of our U.S. federal tax returns for the 2008 and 2009 tax years without any material adjustments.
Current taxes receivable		1,000,000
Federal net operating loss carryforwards	15,800,000	0
State net operating loss carryforward	7,800,000	0
Foreign net operating loss carryforwards	10,900,000
Federal and state net operating loss carryforwards subject to limitations				2,200,000	7,200,000
Valuation allowance	(8,539,000)	(6,453,000)
Unrecognized tax benefit	444,000	780,000
Reduction in income tax expense resulting from recognition of unrecognized tax benefit	$ 300,000