Schedule II - Valuation and Qualifying Accounts: (Tables)

12 Months Ended

Dec. 31, 2017

Notes Tables

Schedule of Valuation and Qualifying Accounts [Table Text Block]

	201 7			201 6
Balance at beginning of year	$	137,000		$	126,000
Charged to expenses		6,000			26,000
Uncollectible accounts written off		(29,000	)		(15,000	)
Balance at end of year	$	114,000		$	137,000

	201 7			2016
Balance at beginning of year	$	794,000		$	823,000
Charged to expenses		-			(11,000	)
Excess inventory written off		(294,000	)		(18,000	)
Balance at end of year	$	500,000		$	794,000

Deferred Tax Asset Valuation Allowance		2017		2016
Beginning Balance	$	45,000	$	45,000
Additions charged (credited) to expense		586,706		-
Balance at end of year	$	631,706	$	45,000

Schedule of Property and Equipment and the Related Depreciation [Table Text Block]

	201 7			201 6
Cost Basis
Balance at beginning of year	$	38,250,000		$	39,025,000
Additions		813,697			-
Disposals		(7,620,697	)		(775,000	)
Balance at end of year	$	31,443,000		$	38,250,000
Accumulated depreciation
Balance at beginning of year	$	32,938,000		$	32,472,000
Depreciation		1,568,697			466,000
Disposals		(7,620,697	)		-
Balance at end of year	$	26,886,000		$	32,938,000