Note 3 - Investments (Tables)

12 Months Ended

Dec. 31, 2017

Notes Tables

Schedule of Available-for-sale Securities Reconciliation [Table Text Block]

	December 31,
	2017			2016
Cost basis	$	543,000		$	543,000
Gain previously recognized on warrants		380,000			380,000
Loss included in accumulated other comprehensive loss		(580,000	)		(316,000	)
Fair value	$	343,000		$	607,000