Note 2 - Discontinued Operations (Details Textual) - USD ($)	1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Released 9 Months from Closing Date Member | Environmental Services [Member] | Ecoserv [Member]
Escrow Deposit	$ 4,000,000	$ 4,000,000	$ 4,000,000
Released 18 Months from Closing Date [Member] | Environmental Services [Member] | Ecoserv [Member]
Escrow Deposit	4,000,000	4,000,000	4,000,000
Environmental Services [Member] | Ecoserv [Member]
Escrow Deposit	8,000,000	8,000,000	$ 8,000,000
Environmental Services [Member]
Proceeds from Divestiture of Businesses	100,000,000
Proceeds from Divestiture of Businesses, Net of Cash Divested	$ 89,800,000
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax		34,000,000
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax		$ 22,100,000
Proceeds from Divestiture of Businesses, Net of Cash Divested				$ 89,766,000	$ 13,329,000
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax				33,974,000
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax				$ 22,117,000