Note 2 - Sales of Subsidiary; Discontinued Operations (Details Textual) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Chem Free [Member] | Discontinued Operations, Disposed of by Sale [Member] | Restricted Cash and Cash Equivalents after Working Capital Adjustment [Member]
Restricted Cash and Cash Equivalents, Current			$ 880,000
Chem Free [Member] | Discontinued Operations, Disposed of by Sale [Member]
Disposal Group, Including Discontinued Operation, Consideration		$ 21,600,000
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax		18,746,000
Disposal Group, Including Discontinued Operation, Deferred Tax Liabilities	$ 120,000
Increase in Restricted Cash		3,300,000
Restricted Cash and Cash Equivalents, Current	$ 2,200,000		2,200,000
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax		$ 18,746,000
Restricted Cash and Cash Equivalents, Current	$ 2,200,000		2,200,000
Disposal Group Including Discontinued Operation, Working Capital Adjustment			$ 220,000