Note 2 - Investments and Restricted Cash (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Jun. 30, 2016	Dec. 31, 2015
Available-for-sale Securities, Current			$ 15,100,000	$ 0
Long-term Investments			4,453,000	1,515,000
Available-for-sale Securities, Amortized Cost Basis			3,200,000	4,000,000
Other than Temporary Impairment Losses, Investments	$ 1,000,000	$ 2,800,000
Restricted Cash and Investments, Current			3,900,000
Restricted Investments			$ 1,000,000	$ 1,000,000