Note 11 - Long-term Debt - Long-term Debt and Convertible Debentures (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Capital leases maturing at various dates through 2021	$ 1,991	$ 1,868
Other long-term debt maturing at various dates up to 2020	1,491	1,549
	249,893	262,498
Long-term debt - current (note 11)	2,426	1,961
Long-term debt - non-current (note 11)	247,467	260,537
Revolving Credit Facility [Member]
Revolving credit facility	$ 246,411	$ 259,081

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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