Geographic Information - External Revenue and Long-Lived Assets by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 18,562	$ 22,933	$ 24,519	$ 22,185	$ 20,570	$ 21,933	$ 21,770	$ 22,265	$ 88,199	$ 86,538	$ 90,564
Long-Lived Assets	4,050				4,533				4,050	4,533
Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	2,808				3,078				2,808	3,078
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									42,933	51,036	55,071
Americas (Excluding the U.S.)
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									6,828	1,507	4,200
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									19,463	20,478	23,206
Long-Lived Assets	1,223				1,429				1,223	1,429
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									18,975	13,517	$ 8,087
Long-Lived Assets	$ 19				$ 26				$ 19	$ 26