Sale of MRI Assets - Schedule of Components of Gain on Sale (Detail) - USD ($)		9 Months Ended
	Jan. 30, 2017	Sep. 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash received		$ 2,850,000
Asset Purchase Agreement [Member] | VersaVue Software and DynaCAD Product and Related Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash received		2,850,000
Holdback reserve	$ 350,000	350,000
Fair value of transition services		(118,000)
Net Assets sold		(574,000)
Total	$ 2,500,000	$ 2,508,000