Segment Reporting and Significant Customer Information - Revenue for Individual Countries that Exceed 10% of Total Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenue, Major Customer [Line Items]
Total revenues	$ 34,804	$ 39,145
United States
Revenue, Major Customer [Line Items]
Total revenues	20,302	23,431
United Kingdom
Revenue, Major Customer [Line Items]
Total revenues	7,121	7,871
Rest of the world
Revenue, Major Customer [Line Items]
Total revenues	$ 7,381	$ 7,843