Note 1 - Basis of Presentation - Property and Equipment (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2018	Dec. 31, 2017
Property and equipment, gross	$ 738,055	$ 719,260
Accumulated depreciation	(395,059)	(368,602)
Total property and equipment, net	342,996	350,658
Land [Member]
Property and equipment, gross	51,946	50,458
Building and Building Improvements [Member]
Property and equipment, gross	$ 157,667	156,924
Building and Building Improvements [Member] \| Minimum [Member]
Estimated Useful Lives (Year)	7 years
Building and Building Improvements [Member] \| Maximum [Member]
Estimated Useful Lives (Year)	40 years
Equipment [Member]
Property and equipment, gross	$ 528,442	$ 511,878
Equipment [Member] \| Minimum [Member]
Estimated Useful Lives (Year)	3 years
Equipment [Member] \| Maximum [Member]
Estimated Useful Lives (Year)	20 years

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business 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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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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