Information about Geographic Areas - Schedule of Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Information about geographic areas
Revenue	$ 8,622	$ 10,574	$ 26,655	$ 36,821
United States
Information about geographic areas
Revenue	2,473	4,060	9,582	17,421
Japan
Information about geographic areas
Revenue	330		330	313
Asia-Pacific ex Japan
Information about geographic areas
Revenue	5,770	6,393	16,593	18,365
Europe and Middle East
Information about geographic areas
Revenue	$ 49	$ 121	$ 150	$ 722