Note 13 - Accumulated Other Comprehensive Income (Loss) - Schedule of AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Balance	$ 49,893	$ 66,894
Other comprehensive income (loss), net of tax	(9,541)	(8,958)
Balance	(25,787)	49,893
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(23,240)	(16,183)
Cumulative-effect adjustment for the adoption of ASU 2017-12
Amounts recognized into AOCI	(1,974)	(7,057)
Currency impact
Amounts reclassified from AOCI
Tax effect	67
Other comprehensive income (loss), net of tax	(1,907)	(7,057)
Balance	(25,147)	(23,240)
Derivative Instruments [Member]
Balance	(2,866)	351
Cumulative-effect adjustment for the adoption of ASU 2017-12		(275)
Amounts recognized into AOCI	(11,130)	(3,242)
Currency impact
Amounts reclassified from AOCI	(250)	(711)	[1]
Tax effect	2,814	1,011
Other comprehensive income (loss), net of tax	(8,566)	(2,942)
Balance	(11,432)	(2,866)
Pension and Other Post-retirement Benefits [Member]
Balance	(88,299)	(89,340)
Cumulative-effect adjustment for the adoption of ASU 2017-12
Amounts recognized into AOCI	(1,143)	(5,245)
Currency impact	(428)	(164)
Amounts reclassified from AOCI	3,884	6,431	[2]
Tax effect	(1,381)	19
Other comprehensive income (loss), net of tax	932	1,041
Balance	(87,367)	(88,299)
AOCI Attributable to Parent [Member]
Balance	(114,405)	(105,172)
Cumulative-effect adjustment for the adoption of ASU 2017-12		(275)
Amounts recognized into AOCI	(14,247)	(15,544)
Currency impact	(428)	(164)
Amounts reclassified from AOCI	3,634	5,720
Tax effect	1,500	1,030
Other comprehensive income (loss), net of tax	(9,541)	(8,958)
Balance	$ (123,946)	$ (114,405)

[1] We reclassified natural gas contracts through cost of sales and the interest rate swaps through interest expense on the Consolidated Statements of Operations. See note 12 for additional information.

[2] We reclassified the net pension and non-pension post-retirement benefits amortization and settlement charges through other income (expense) on the Consolidated Statements of Operations. See notes 8 and 9 for additional information.