Information about Geographic Areas and Operating Segments - Revenue and Long-Lived Assets by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Total revenue:
Total revenue	$ 22,841	$ 25,439
Long-lived assets:
Total long-lived assets	5,311		$ 5,351
North America [Member]
Total revenue:
Total revenue	21,770	24,067
Long-lived assets:
Total long-lived assets	989		1,025
Asia [Member]
Total revenue:
Total revenue	249	275
Long-lived assets:
Total long-lived assets	90		90
Europe [Member]
Total revenue:
Total revenue	822	$ 1,097
Long-lived assets:
Total long-lived assets	$ 4,232		$ 4,236