Information about Geographic Areas - Revenue and Long-Lived Assets by Geographic Area (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Total revenue:
Total revenue	$ 24,535	$ 23,572	$ 70,321	$ 66,279
Long-lived assets:
Total long-lived assets	6,514		6,514		5,625
North America [Member]
Total revenue:
Total revenue	22,456	20,875	62,955	59,714
Long-lived assets:
Total long-lived assets	1,669		1,669		678
Asia [Member]
Total revenue:
Total revenue	830	1,379	3,581	3,129
Long-lived assets:
Total long-lived assets	365		365		403
Europe [Member]
Total revenue:
Total revenue	1,249	1,318	3,785	3,436
Long-lived assets:
Total long-lived assets	$ 4,480		$ 4,480		$ 4,544