Segment Information - Geographical Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 27,023	$ 28,773	$ 77,626	$ 101,476
Property and equipment, net	3,242		3,242		$ 4,728
Total Intangible Assets, Net	2,189		2,189		6,862
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	12,582	11,223	31,570	49,151
Property and equipment, net	2,055		2,055		2,974
Total Intangible Assets, Net					6,862
Foreign Countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	14,441	17,550	46,056	52,325
Property and equipment, net	1,187		1,187		1,754
Other North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	93	269	386	703
Property and equipment, net	3		3		33
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	2,822	5,703	12,267	17,819
Property and equipment, net	1,184		1,184		1,721
CHINA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	39		39		163
INDIA
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	1,145		1,145		$ 1,558
Netherlands [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	8,257	7,849	20,370	21,450
Other EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	3,269	3,729	13,033	12,353
Europe, the Middle East and Africa [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 11,526	$ 11,578	$ 33,403	$ 33,803