Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Taxes [Abstract]
Provision for income taxes	$ 43	$ 30	$ 123	$ 61
Effective tax rate (as a percent)	(0.30%)	7.00%	(0.60%)	2.80%