Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Income Taxes
Income Tax Expense (Benefit)	$ 73	$ 2	$ 119	$ 17
Current income tax expense (benefit)
Current federal income tax expense (benefit)		0		0
Current state income tax expense (benefit)		0		0
Components of deferred tax assets and liabilities
Gross unrecognized tax benefits	200		200		$ 200
Maximum | Foreign
Income Taxes
Income Tax Expense (Benefit)	$ 100	$ 100	$ 100	$ 100