Derivative Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2011

Derivative Financial Instruments (Tables) [Abstract]

Fair value of derivative instruments

	Asset Derivatives				Liability Derivatives
(in thousands)	2011		2010		2011		2010
Derivatives designated as hedging instruments:
Interest rate swaps—cash flow hedges	$	—	$	—	$	—	$	12,227
Natural gas swaps		—		22		—		248
Total derivatives designated as hedging instruments	$	—	$	22	$	—	$	12,475

Effect of derivative instruments on the statement of operations

	Amount of Gain (Loss) Recognized in OCI on Derivative							Amount Reclassified from Accumulated OCI
Derivatives in Cash Flow	(Effective Portion)						Location of Amount Reclassified from	into Income
Hedging Relationships	2011			2010			Accumulated OCI into Income	2011		2010
Interest rate swaps	$	(447	)	$	(6,720	)	Interest expense, net of amounts capitalized	$	12,674	$	20,154
Natural gas swaps		(533	)		(521	)	Operating costs		759		295
Total	$	(980	)	$	(7,241	)	Total	$	13,433	$	20,449

Derivatives Not Designated as	Location of Gain Recognized in Income on	Amount of Gain Recognized in Income on Derivative
Hedging Instruments	Derivatives	2011		2010
Natural gas swaps	Other gains and (losses), net	$	—	$	202