Provision Benefit for Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Components Of Income Tax Expense Benefit [Line Items]
Foreign	$ 168us-gaap_CurrentForeignTaxExpenseBenefit	$ 191us-gaap_CurrentForeignTaxExpenseBenefit	$ 180us-gaap_CurrentForeignTaxExpenseBenefit
Federal	0us-gaap_CurrentFederalTaxExpenseBenefit	0us-gaap_CurrentFederalTaxExpenseBenefit	0us-gaap_CurrentFederalTaxExpenseBenefit
State	1	0	0
Total Current	169us-gaap_CurrentIncomeTaxExpenseBenefit	191us-gaap_CurrentIncomeTaxExpenseBenefit	180us-gaap_CurrentIncomeTaxExpenseBenefit
Foreign	0	0	0
Federal	22	21	48
State	4	6	14
Total Deferred	26us-gaap_DeferredIncomeTaxExpenseBenefit	27us-gaap_DeferredIncomeTaxExpenseBenefit	62us-gaap_DeferredIncomeTaxExpenseBenefit
Provision for income taxes	$ 195us-gaap_IncomeTaxExpenseBenefit	$ 218us-gaap_IncomeTaxExpenseBenefit	$ 242us-gaap_IncomeTaxExpenseBenefit

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