Summary of Deferred Revenue (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Components of deferred revenue
Undelivered elements (training, installation, and product and support services)	$ 1,364	$ 1,608
Extended warranty contracts	1,432	1,428
Deferred royalties	231	261
Total Deferred Revenue	3,027	3,297
Less long-term amounts:
Deferred royalties	112	142
Total Deferred Revenue - Long-Term	112	142
Deferred revenue, current portion	$ 2,915	$ 3,155