Details of Certain Financial Statement Components and Supplemental Disclosures of Cash Flow Information and Non-Cash Activities - Components of Patents, Licenses and Purchased Technology (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Patents, Licenses and Purchased Technology:
Less accumulated amortization	$ (869,000)	$ (795,000)
Patents, licenses and purchased technology, net	938,000	886,000
Patent Pending [Member]
Patents, Licenses and Purchased Technology:
Patents, licenses and purchased technology, gross	555,000	454,000
Patents Issued [Member]
Patents, Licenses and Purchased Technology:
Patents, licenses and purchased technology, gross	1,252,000	1,226,000
Less accumulated amortization	(869,000)	(795,000)
Patents, licenses and purchased technology, net	$ 383,000	$ 432,000