Note 14 - Long-term Debt and Credit Arrangements - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Total debt	$ 364,164	$ 364,352	$ 380,571
Debt issuance costs and other	6,994	6,906	(804)
Long-term Debt, Current Maturities, Total	8,253	8,244	47,281
Long-term Debt, Excluding Current Maturities, Total	355,911	356,108	333,290
Convertible Debt [Member] | The 2.75% Convertible Notes [Member]
Total debt	195,295	193,696	0
Term Loan [Member] | The Credit Agreement [Member]
Total debt	136,875	138,750	144,375
Long-term Debt, Current Maturities, Total	7,500	7,500	7,500
Long-term Debt, Excluding Current Maturities, Total	129,400	131,300	136,900
Line of Credit [Member] | The Credit Agreement [Member] | Revolving Credit Facility [Member]
Total debt	25,000	25,000	197,000
Senior Notes [Member] | The 2019 Notes [Member]
Total debt	$ 0	$ 0	$ 40,000