Derivatives (Tables)

3 Months Ended

Mar. 31, 2015

Derivative Instruments, Gain (Loss) [Line Items]

Schedule of Derivative Assets and Liabilities at Fair Value

The following table provides the fair values of our derivative financial instruments for the periods presented:

	Asset Derivatives:
(dollars in thousands)	March 31, 2015			December 31, 2014
Derivatives not designated as hedging instruments under FASB ASC 815:	Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
Currency contracts	Prepaid and other current assets	$	477	Prepaid and other current assets	$	403
Total undesignated		477			403
Total		$	477		$	403
	Liability Derivatives:
(dollars in thousands)	March 31, 2015			December 31, 2014
Derivatives designated as hedging instruments under FASB ASC 815:	Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
Natural gas contracts	Derivative liability - current	$	1,453	Derivative liability - current	$	1,222
Natural gas contracts	Other long-term liabilities	165		Other long-term liabilities	103
Total designated		1,618			1,325
Derivatives not designated as hedging instruments under FASB ASC 815:
Natural gas contracts	Derivative liability - current	1,698		Derivative liability - current	1,431
Natural gas contracts	Other long-term liabilities	173		Other long-term liabilities	112
Total undesignated		1,871			1,543
Total		$	3,489		$	2,868

Summary of the Effective Portion of Derivative Gain (Loss) Recognized in Other Comprehensive Income (Loss)

The following table provides a summary of the effective portion of derivative gain (loss) recognized in other comprehensive income (loss):

	Three months ended March 31,
(dollars in thousands)	2015			2014
Derivatives in Cash Flow Hedging relationships:
Natural gas contracts	$	(829	)	$	630
Total	$	(829	)	$	630

Reclassification out of Accumulated Other Comprehensive Income

The following table provides a summary of the effective portion of derivative gain (loss) reclassified from accumulated other comprehensive loss to the Condensed Consolidated Statements of Operations:

		Three months ended March 31,
(dollars in thousands)		2015			2014
Derivative:	Location:
Natural gas contracts	Cost of sales	$	(536	)	$	465
Total impact on net income (loss)		$	(536	)	$	465

Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location

Gains (losses) on derivatives that were not designated as hedging instruments are recorded in current earnings as follows:

		Three months ended March 31,
(dollars in thousands)		2015		2014
Derivative:	Location:
Currency contracts	Other income (expense)	$	74	$	—
Total		$	74	$	—

Natural Gas Contracts

Derivative Instruments, Gain (Loss) [Line Items]

Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block]

The following table provides a summary of the gain (loss) recognized in other income (expense) in the Condensed Consolidated Statements of Operations from our natural gas contracts:

	Three months ended March 31,
(dollars in thousands)	2015			2014
De-designated contracts	$	(104	)	$	—
Contracts where hedge accounting was not elected	(295		)	—
Total	$	(399	)	$	—