Fair Value (Tables)

6 Months Ended

Jun. 30, 2014

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, 2014										December 31, 2013
	Level 1		Level 2			Level 3		Total			Level 1		Level 2			Level 3		Total
Commodity futures natural gas contracts	$	—	$	106		$	—	$	106		$	—	$	413		$	—	$	413
Currency contracts	—		(187		)	—		(187		)	—		—			—		—
Interest rate agreement	—		—			—		—			—		(2,073		)	—		(2,073		)
Net derivative asset (liability)	$	—	$	(81	)	$	—	$	(81	)	$	—	$	(1,660	)	$	—	$	(1,660	)

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, 2014			December 31, 2013
Prepaid and other current assets	$	182		$	394
Other assets	—			19
Accrued liabilities	(187		)	—
Other long-term liabilities	(76		)	(2,073		)
Net derivative asset (liability)	$	(81	)	$	(1,660	)