Note 8 - Long-term Debt and Credit Facility - Long-term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Long term debt	$ 302,236	$ 314,219
Less – Current maturities of long-term debt	35,736	29,469
Less – Unamortized loan costs	2,253	2,747
Total	264,247	282,003
Medium-term Notes [Member]
Long term debt	262,500	282,188
Line of Credit [Member]
Long term debt	39,000	31,000
Notes Payable, Other Payables [Member]
Long term debt	$ 736	$ 1,031

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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