Note 12 - Marketable Securities - Marketable Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Gross Unrealized Gains - Equity securities	$ 406	$ 398
Marketable equity securities	6,502	5,909
Gross Unrealized Gains - Debt securities		(1)
Estimated Fair Value - Debt securities	1,599	1,655
Amortized Cost - Total marketable securities	8,101	7,565
Gross Unrealized Gains - Total marketable securities	406	397
Estimated Fair Value - Total marketable securities	8,101	7,564
Amortized Cost [Member]
Amortized Cost - Equity securities	6,096	5,511
Amortized Cost - Debt securities	1,599	1,656
Amortized Cost - Total marketable securities	$ 7,695	$ 7,167