Note 1 - Basis of Presentation (Tables)

6 Months Ended

Jun. 30, 2015

Disclosure Text Block [Abstract]

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

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2015		2014		2015		2014
Weighted-average shares outstanding-basic		71,637		57,862		64,968		57,855
Common stock equivalents - stock options and restricted stock		633		449		561		443
Weighted-average shares outstanding-diluted		72,270		58,311		65,529		58,298

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

	June 30,			December 31,
	2015			2014
Accumulated balances of items included in accumulated other comprehensive loss:
Increase in pension liability	$	(21,830	)	$	(34,117	)
Income tax benefit		(8,512	)		(13,305	)
Accumulated other comprehensive loss	$	(13,318	)	$	(20,812	)

Property, Plant and Equipment [Table Text Block]

							Estimated
	June 30,			December 31,			Useful Lives
	2015			2014			(in years)
Property and equipment:
Land	$	32,139		$	32,085
Buildings and improvements		77,940			77,477			7 to 40
Equipment		395,150			394,569			3 to 20
		505,229			504,131
Accumulated depreciation		(295,026	)		(282,320	)
Total property and equipment, net	$	210,203		$	221,811