Segment Information (Revenue by Geographic Region) (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	[1]	$ 28,230	$ 30,597
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue		10,383	12,349
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue		3,384	4,163
Republic of Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue		9,233	6,324
Rest of the World
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue		$ 5,230	$ 7,761

[1] Quarters ended March 31, 2016 quarter ended March 31, 2016Components of Revenue License Fees5,777 7,289Service Revenue22,453 23,308Net Revenue28,230 30,597