Fair Value (Tables)

12 Months Ended

Dec. 31, 2012

Fair Value Disclosures [Abstract]

Fair Value of Derivatives

	Fair Value at										Fair Value at
Asset / (Liability (dollars in thousands)	December 31, 2012										December 31, 2011
	Level 1		Level 2			Level 3		Total			Level 1		Level 2			Level 3		Total
Commodity futures natural gas contracts	$	—	$	(420	)	$	—	$	(420	)	$	—	$	(3,688	)	$	—	$	(3,688	)
Currency contracts	—		41			—		41			—		107			—		107
Interest rate agreements	—		298			—		298			—		3,606			—		3,606
Net derivative asset (liability)	$	—	$	(81	)	$	—	$	(81	)	$	—	$	25		$	—	$	25

Total Derivative Position Recorded on Balance Sheet

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

Asset / (Liability (dollars in thousands)	December 31, 2012			December 31, 2011
Prepaid and other current assets	$	41		$	107
Derivative asset	298			3,606
Derivative liability	(420		)	(3,390		)
Other long-term liabilities	—			(298		)
Net derivative asset (liability)	$	(81	)	$	25