Note 1 - Description of Business and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

Schedule of Principal Transactions Revenue [Table Text Block]

	Year Ended December 31,
	2018			2017			2016
Trade revenue	$	2,897		$	1,832		$	2,069
Trade expense		(3,012	)		(1,863	)		(1,997	)
Net trade (loss) income	$	(115	)	$	(31	)	$	72

Property, Plant and Equipment [Table Text Block]

							Estimated
	December 31,						Useful Lives
	2018			2017			(in years)
Property and equipment:
Land	$	52,511		$	50,458
Buildings and improvements		166,200			156,924			7	to	40
Equipment		547,707			511,878			3	to	20
		766,418			719,260
Accumulated depreciation		(403,276	)		(368,602	)
Total property and equipment, net	$	363,142		$	350,658

Schedule of Disposal of Assets and Purchase of Property and Equipment [Table Text Block]

	Year ended December 31,
	2018			2017			2016
Gain (loss) on disposal of assets, net:
Proceeds from sale of assets	$	8,967		$	90,927		$	44,234
Proceeds from Repack		14,217			84			-
Net book value of assets disposed		(6,779	)		(16,811	)		(44,563	)
Total	$	16,405		$	74,200		$	(329	)
Purchase of property and equipment:
Recurring purchases - operations	$	40,983		$	31,692		$	43,604
Repack		27,081			2,824			-
Repack related		1,911			-			-
Total	$	69,975		$	34,516		$	43,604

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

	Year Ended December 31,
	2018		2017		2016
Weighted-average shares outstanding, basic		88,084		73,061		71,848
Weighted-average shares underlying stock options and restricted shares		694		775		916
Weighted-average shares outstanding, diluted		88,778		73,836		72,764

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

	December 31,
	2018			2017
Accumulated balances of items included in accumulated other comprehensive loss:
Increase in pension liability	$	(35,280	)	$	(36,336	)
Income tax benefit		(13,903	)		(14,171	)
Accumulated other comprehensive loss	$	(21,377	)	$	(22,165	)