Note 3 - Joint Venture - Certain Financial Information About the Joint Venture Included On the Company's Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property, plant and equipment, net of accumulated depreciation of $285 and $211	$ 368,570	$ 366,113
ACS Cable Systems LLC and Quintillion Holdings, LLC Joint Venture [Member]
Cash	270	190
Property, plant and equipment, net of accumulated depreciation of $285 and $211	$ 1,856	$ 1,930

Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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