Business Segments (Detail Textuals)	9 Months Ended	12 Months Ended
	Sep. 30, 2018 USD ($) Segment	Dec. 31, 2017 USD ($) Segment
Segment Reporting Information [Line Items]
Total identifiable assets	$ 40,803,000	$ 37,986,000
Number of operating segments | Segment	2	2
Operating Segments
Segment Reporting Information [Line Items]
Total identifiable assets	$ 40,803,000	$ 37,986,000
Operating Segments | ATG
Segment Reporting Information [Line Items]
Total identifiable assets	29,896,000	26,331,000
Operating Segments | CPG
Segment Reporting Information [Line Items]
Total identifiable assets	$ 10,907,000	$ 11,655,000