Note 11 - Segment Reporting - Segment Information (Details) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Assets		$ 58,356,082	$ 46,545,000	$ 58,356,082	$ 46,545,000	$ 58,978,250
Revenue		6,435,278	10,829,709	15,589,111	20,480,326
Operating income/(loss)		(1,379,613)	1,830,787	(469,045)	3,547,576
Pretax income/(loss)		(1,470,000)	1,831,000	(663,000)	3,540,000
Corporate, Non-Segment [Member]
Assets		1,552,000	1,952,000	1,552,000	1,952,000
Revenue
Operating income/(loss)		(655,000)	(510,000)	(1,299,000)	1,050,000
Pretax income/(loss)		(745,000)	(510,000)	(1,493,000)	(1,058,000)
Intersegment Eliminations [Member]
Assets	[1]
Revenue	[1]	(402,000)	(354,000)	(586,000)	(1,408,000)
Operating income/(loss)	[1]
Pretax income/(loss)	[1]	(643,000)		(1,299,000)
CVD [Member] | Operating Segments [Member]
Assets		35,841,000	38,216,000	35,841,000	38,216,000
Revenue		5,635,000	9,404,000	12,341,000	18,077,000
Operating income/(loss)		145,000	1,753,000	1,482,000	3,409,000
Pretax income/(loss)		145,000	1,753,000	1,482,000	3,409,000
SDC [Member] | Operating Segments [Member]
Assets		3,481,000	5,540,000	3,481,000	5,540,000
Revenue		844,000	1,780,000	3,104,000	3,812,000
Operating income/(loss)		(243,000)	588,000	488,000	1,190,000
Pretax income/(loss)		(243,000)	588,000	488,000	1,190,000
Materials [Member] | Operating Segments [Member]
Assets		17,481,000	837,000	17,481,000	837,000
Revenue		358,000		730,000
Operating income/(loss)		(627,000)		(1,140,000)
Pretax income/(loss)		$ (627,000)		$ (1,140,000)

[1] All elimination entries represent intersegment revenues eliminated in consolidation for external financial reporting.