Summary of Deferred Revenue (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Components of deferred revenue
Undelivered elements (training, installation, and product and support services)	$ 1,075	$ 1,404
Extended warranty contracts	1,499	1,487
Deferred royalties	112	142
Total Deferred Revenue	2,686	3,033
Less long-term amounts:
Deferred royalties	20	23
Total Deferred Revenue - Long-Term	20	23
Total Deferred Revenue - Current	$ 2,666	$ 3,010