Segment Information (Continuing Operating Segments) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) segment	Dec. 31, 2015 USD ($) segment
Net revenues	$ 7,087	$ 7,636
Interest income	20	0
Depreciation and amortization	313	348
Interest expense	1	11
Purchase of property and equipment	8	70
Total assets	13,058	13,421
Income before income taxes	$ 204	$ 1,744
Number of reportable segments | segment	1	2
Foreign Country Revenue [Member]
Net revenues		$ 972
Production Monitoring [Member]
Net revenues		7,636
Interest income		0
Depreciation and amortization		348
Interest expense		11
Purchase of property and equipment		70
Total assets		4,998
Income before income taxes		295
Production Monitoring [Member] | Foreign Country Revenue [Member]
Net revenues		972
ESI Investment Company [Member]
Interest income		0
Total assets		8,423
Income before income taxes		$ 1,449