Note 1 - Basis of Presentation (Tables)

3 Months Ended

Mar. 31, 2015

Disclosure Text Block [Abstract]

Schedule of Weighted Average Number of Shares [Table Text Block]

	Three Months Ended
	March 31,
	2015		2014
Weighted-average shares outstanding-basic		58,224		57,847
Common stock equivalents for stock options and restricted stock		513		439
Weighted-average shares outstanding-diluted		58,737		58,286

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

	March 31,			December 31,
	2015			2014
Accumulated balances of items included in accumulated other comprehensive loss:
Increase in pension liability	$	(34,117	)	$	(34,117	)
Income tax benefit		(13,305	)		(13,305	)
Accumulated other comprehensive loss	$	(20,812	)	$	(20,812	)

Property, Plant and Equipment [Table Text Block]

	March 31,			December 31,			Estimated Useful Lives
	2015			2014			(in years)
Property and equipment:
Land	$	32,114		$	32,085
Buildings and improvements		77,780			77,477			7 to 40
Equipment		394,590			394,569			3 to 20
		504,484			504,131
Accumulated depreciation		(290,690	)		(282,320	)
Total property and equipment, net	$	213,794		$	221,811