Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at beginning of period			$ 72,301
Balance at end of period	$ 67,950		67,950
Foreign currency translation
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at beginning of period	(535)	$ (340)	(471)	$ 18
Total other comprehensive (loss) income	(642)	(135)	(706)	(493)
Balance at end of period	(1,177)	(475)	(1,177)	(475)
Available-for-sale marketable securities
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at beginning of period	23	34	23	19
Other comprehensive (loss) income	(3)	(20)	(3)	5
Deferred income taxes	0	8	0	(2)
Total other comprehensive (loss) income	(3)	(12)	(3)	3
Balance at end of period	20	22	20	22
Total accumulated other comprehensive loss
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at end of period	$ (1,157)	$ (453)	$ (1,157)	$ (453)