Information about Geographic Areas (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Information about geographic areas
Revenue	$ 45,322	$ 47,695	$ 67,406
United States
Information about geographic areas
Revenue	28,327	42,350	47,752
Japan
Information about geographic areas
Revenue	2,848	2,726	12,691
APAC other
Information about geographic areas
Revenue	13,074	1,781	2,958
Europe and Middle East
Information about geographic areas
Revenue	$ 1,073	$ 838	$ 4,005