Note 2 - Discontinued Operations (Details Textual) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax			$ 18,802,000
Restricted Cash and Cash Equivalents, Current			2,200,000
Disposal Group Including Discontinued Operation, Working Capital Adjustment			220,000
Disposal Group, Including Discontinued Operation, Liabilities, Current			120,000
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		18,802,000
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation			56,000
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
Disposal Group, Including Discontinued Operation, Liabilities, Current			120,000
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