Note 2 - Sale of Subsidiary; Discontinued Operations (Details Textual) - USD ($)	3 Months Ended				9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 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]
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
Increase in Restricted Cash			3,300,000
Disposal Group Including Discontinued Operation, Working Capital Adjustment		$ 20,000	$ 200,000
Restricted Cash and Cash Equivalents, Noncurrent	$ 2,200,000				2,200,000
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax					18,726,000
Restricted Cash and Cash Equivalents, Noncurrent	$ 2,200,000				$ 2,200,000