Note 1 - Organization, Nature of Business and Summary of Significant Accounting Policies (Details Textual) $ in Thousands			3 Months Ended	12 Months Ended
	Jan. 01, 2018 USD ($)	Jun. 29, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Stock Conversion Ratio				1
Cash and Cash Equivalents, at Carrying Value				$ 113,887	$ 181,242
Allowance for Doubtful Accounts Receivable				4,300	3,000
Provision for Doubtful Accounts				4,444	1,700	$ 8,100
Depreciation				136,500	206,700	261,800
Asset Impairment Charges
Amortization of Debt Issuance Costs				608
Accumulated Amortization, Debt Issuance Costs				$ 600	58,800
Number of Reportable Segments				2
Income (Loss) from Equity Method Investments				$ (83)	(5,700)	500
Unrecognized Tax Benefits, Period Increase (Decrease)				6,500
Debt Issuance Costs, Net					0
Accounting Standards Update 2016-16 [Member] | Subsequent Event [Member]
Cumulative Effect on Retained Earnings, Net of Tax	$ 13,200
Other Noncurrent Assets [Member]
Equity Method Investments				2,800	9,000
Interest Expense [Member]
Amortization of Debt Issuance Costs				600	48,300	$ 10,900
Specialty Chemical Supplies Business [Member]
Proceeds from Sale of Productive Assets		$ 9,300
Directional Drilling, Cementing, Artificial Lift Applications and International Coiled Tubing [Member]
Asset Impairment Charges			$ 393,100	$ 0	61,100
Minimum [Member]
Property, Plant and Equipment, Useful Life				3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life				25 years
Captive Insurance Subsidiaries [Member]
Cash and Cash Equivalents, at Carrying Value				$ 23,800	$ 16,100
Years 2008 through December 31, 2014 [Member] | Correction of Overstatement From Over Accrual of Direct Costs [Member]
Prior Period Reclassification Adjustment			$ 9,800