Note 18 - Retirement Plans (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Number of Actuarial Equivalent Installments	10
Defined Benefit Plan, Settlements, Plan Assets			$ 17,381
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements			(7,170)
Defined Contribution Plan, Cost Recognized	$ 1,294	1,081	941
Equity Securities [Member]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	30.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	80.00%
Fixed Income Funds [Member]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	25.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	45.00%
All Other Investments [Member]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	5.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	15.00%
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements
Defined Benefit Plan, Funded Status of Plan	(1,209)	(1,800)
Foreign Pension Plan [Member]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements
Defined Benefit Plan, Funded Status of Plan	(25,002)	(22,748)
Defined Benefit Plan, Accumulated Benefit Obligation	24,134
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	0
United States Pension Plan of US Entity [Member]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements			$ (7,170)
Defined Benefit Plan, Accumulated Benefit Obligation	57,718
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets	18,194
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	$ 1,585