Note 8 - Long-term Debt and Credit Facility - Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Long term debt	$ 303,668	$ 278,520
Less – Current maturities of long-term debt	29,735	32,803
Less – Unamortized loan costs	1,923	2,088
Total	272,010	243,629
Medium-term Notes [Member]
Long term debt	245,000	253,750
Line of Credit [Member]
Long term debt	58,000	24,000
Notes Payable, Other Payables [Member]
Long term debt	$ 668	$ 770

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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

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