Note 1 - Basis of Presentation (Details) - Property and Equipment - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Property and equipment:
Property, plant and equipment, gross	$ 505,229	$ 504,131
Accumulated depreciation	(295,026)	(282,320)
Total property and equipment, net	210,203	221,811
Land [Member]
Property and equipment:
Property, plant and equipment, gross	32,139	32,085
Building and Building Improvements [Member]
Property and equipment:
Property, plant and equipment, gross	77,940	77,477
Equipment [Member]
Property and equipment:
Property, plant and equipment, gross	$ 395,150	$ 394,569
Minimum [Member] | Building and Building Improvements [Member]
Property and equipment:
Property, plant and equipment, estimated useful life	7 years
Minimum [Member] | Equipment [Member]
Property and equipment:
Property, plant and equipment, estimated useful life	3 years
Maximum [Member] | Building and Building Improvements [Member]
Property and equipment:
Property, plant and equipment, estimated useful life	40 years
Maximum [Member] | Equipment [Member]
Property and equipment:
Property, plant and equipment, estimated useful life	20 years