Note 10 - Long-term Debt - Long-term Debt and Convertible Debentures (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Revolving Credit Facility	$ 430,167	$ 246,411
Senior Notes	239,577
Capital leases maturing at various dates through 2021	1,470	1,991
Other long-term debt maturing at various dates up to 2021	910	1,491
Long-term debt	672,123	249,893
Long-term debt - current (note 10)	1,834	2,426
Long-term debt - non-current (note 10)	$ 670,289	$ 247,467

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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