Fair Value (Tables)

6 Months Ended

Jun. 30, 2012

Fair Value Disclosures [Abstract]

Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]

	Fair Value at										Fair Value at
Asset / (Liability) (dollars in thousands)	June 30, 2012										December 31, 2011
	Level 1		Level 2			Level 3		Total			Level 1		Level 2			Level 3		Total
Commodity futures natural gas contracts	$	—	$	(2,001	)	$	—	$	(2,001	)	$	—	$	(3,688	)	$	—	$	(3,688	)
Currency contracts	—		36			—		36			—		107			—		107
Interest rate agreements	—		(188		)	—		(188		)	—		3,606			—		3,606
Net derivative (liability) asset	$	—	$	(2,153	)	$	—	$	(2,153	)	$	—	$	25		$	—	$	25

Fair Value, by Balance Sheet Grouping [Table Text Block]

The total derivative position is recorded on the Condensed Consolidated Balance Sheets as follows:

Asset / (Liability (dollars in thousands)	June 30, 2012			December 31, 2011
Prepaid and other current assets	$	36		$	107
Derivative asset	10			3,606
Derivative liability	(2,011		)	(3,390		)
Other long-term liabilities	(188		)	(298		)
Net derivative (liability) asset	$	(2,153	)	$	25