Fair Value (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Fair Value of Derivatives

The fair value of our derivative financial instruments by level is as follows:

	Fair Value at										Fair Value at
Asset / (Liability (dollars in thousands)	December 31, 2015										December 31, 2014
	Level 1		Level 2			Level 3		Total			Level 1		Level 2			Level 3		Total
Commodity futures natural gas contracts	$	—	$	(2,202	)	$	—	$	(2,202	)	$	—	$	(2,868	)	$	—	$	(2,868	)
Currency contracts	—		245			—		245			—		403			—		403
Interest rate agreements	—		(2,378		)	—		(2,378		)	—		—			—		—
Net derivative asset (liability)	$	—	$	(4,335	)	$	—	$	(4,335	)	$	—	$	(2,465	)	$	—	$	(2,465	)

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, 2015			December 31, 2014
Prepaid and other current assets	$	245		$	403
Derivative liability	(4,265		)	(2,653		)
Other long-term liabilities	(315		)	(215		)
Net derivative asset (liability)	$	(4,335	)	$	(2,465	)