Note 18 - Retirement Plans (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) Installment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Number of Actuarial Equivalent Installments | Installment	10
Defined Contribution Plan, Cost	$ 1,745	$ 1,491	$ 1,294
Minimum [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	30.00%
Minimum [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	25.00%
Minimum [Member] | All Other Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	5.00%
Maximum [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	80.00%
Maximum [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	45.00%
Maximum [Member] | All Other Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	15.00%
Accounting Standards Update 2017-07 [Member] | Other Expenses, Net [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, other costs	$ 813
Accounting Standards Update 2017-07 [Member] | Restatement Adjustment [Member] | Selling, General and Administrative Expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, other costs		1,484	1,540
Accounting Standards Update 2017-07 [Member] | Restatement Adjustment [Member] | Cost of Goods Sold [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, other costs		216	$ 163
Pension Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan	30,166	$ 29,423
Defined Benefit Plan, Accumulated Benefit Obligation	28,982
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Accumulated Benefit Obligation	53,421
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets	12,880
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 255