Financial Results by Quarter Financial Resutls by Quarter (Tables)

12 Months Ended

Dec. 31, 2012

Quarterly Financial Data [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

(Dollars in thousands – except per-share amounts)

	THREE MONTHS ENDED
	MARCH 31				JUNE 30				SEPTEMBER 30				DECEMBER 31
	2012		2011		2012		2011		2012		2011		2012		2011
Revenues	$	112,384	$	122,233	$	117,540	$	112,370	$	151,911	$	152,891	$	143,299	$	109,927
Costs and expenses:
Cost of goods sold	88,975		93,148		88,688		85,906		109,806		108,420		103,197		94,778
Selling, general and administrative expenses	10,890		11,927		11,762		8,704		13,342		7,837		13,425		12,081
Environmental remediation charge	—		—		—		—		—		—		—		1,200
Asset impairment charge	—		—		—		—		—		1,180		107		—
	99,865		105,075		100,450		94,610		123,148		117,437		116,729		108,059
Operating income	12,519		17,158		17,090		17,760		28,763		35,454		26,570		1,868
Net income (loss)	$	5,051	$	7,696	$	5,080	$	8,449	$	18,599	$	25,599	$	13,864	$	(1,478	)
Net income (loss) per share1
Basic	$	0.13	$	0.19	$	0.13	$	0.21	$	0.46	$	0.64	$	0.34	$	(0.04	)
Diluted	0.13		0.19		0.13		0.21		0.46		0.63		0.34		(0.04		)

¹   Per-share amounts are computed independently for each of the quarters presented. Therefore, the sum of the quarterly per-share amounts may not equal the total computed for the year.