Note 11 - Marketable Securities (Details) - Marketable Securities - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Available-for-sale:
Gross Unrealized Gains - Equity securities		$ 398	$ 46,197
Estimated Fair Value - Equity securities		5,909	87,659
Held-to-maturity:
Gross Unrealized Gains - Debt Securities		(1)	(200)
Estimated Fair Value - Debt Securities		1,655	2,376
Amortized Cost - Total marketable securities	[1]	7,565	90,235
Gross Unrealized Gains - Total marketable securities		397	45,997
Estimated Fair Value - Total marketable securities		7,564	90,035
Amortized Cost [Member]
Available-for-sale:
Amortized Cost - Equity securities		5,511	41,462
Held-to-maturity:
Amortized Cost - Debt securities		1,656	2,576
Amortized Cost - Total marketable securities		$ 7,167	$ 44,038

[1] As of December 31, 2015 and 2014, the Company determined that $5.9 million and $87.7 million, respectively, of the Marketable securities estimated fair value were classified within Level 1 of the fair value hierarchy and the remaining $1.7 million and $2.3 million, respectively, were classified within Level 3 of the fair value hierarchy.