Note 2 - Sale of Subsidiary; Discontinued Operations (Details Textual) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Discontinued Operations, Disposed of by Sale [Member] | Chem Free [Member] | Restricted Cash and Cash Equivalents after Working Capital Adjustment [Member]
Restricted Cash and Cash Equivalents, Current	$ 880,000			$ 880,000
Discontinued Operations, Disposed of by Sale [Member] | Chem Free [Member] | Restricted Cash and Cash Equivalents before Working Capital Adjustment [Member]
Restricted Cash and Cash Equivalents, Current	1,100,000			1,100,000
Discontinued Operations, Disposed of by Sale [Member] | Chem Free [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	181,000			181,000
Increase in Restricted Cash		3,300,000
Disposal Group Including Discontinued Operation, Working Capital Adjustment	20,000	$ 200,000		220,000
Restricted Cash and Cash Equivalents, Noncurrent	2,200,000			2,200,000
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	(20,000)			18,726,000
Restricted Cash and Cash Equivalents, Current	880,000			880,000
Restricted Cash and Cash Equivalents, Noncurrent	$ 2,200,000			$ 2,200,000