Note 13 - Long-term Debt and Credit Arrangements - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Total debt	$ 339,910	$ 338,800	$ 413,897
Debt issuance costs and other	8,742	7,247	7,166
Long-term Debt, Current Maturities, Total	8,718	8,278	8,253
Long-term Debt, Excluding Current Maturities, Total	331,192	330,522	405,644
Convertible Debt [Member] \| The 2.75% Convertible Notes [Member]
Total debt	205,543	200,303	198,606
Term Loan [Member] \| The Credit Agreement [Member]
Total debt	125,625	131,250	133,125
Long-term Debt, Current Maturities, Total	7,500	7,500	7,500
Long-term Debt, Excluding Current Maturities, Total	118,100	123,800	125,600
Line of Credit [Member] \| The Credit Agreement [Member] \| Revolving Credit Facility [Member]
Total debt	$ 0	$ 0	$ 75,000

The amount or adjustment of other long-term debt.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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