Derivative Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2011

Derivative Financial Instruments (Tables) [Abstract]

Fair value of derivative instruments

	Asset Derivatives				Liability Derivatives
			December 31,				December 31,
	June 30, 2011		2010		June 30, 2011		2010
Derivatives designated as hedging instruments:
Interest rate swaps	$	—	$	—	$	1,529	$	12,227
Natural gas swaps		—		22		220		248
Total derivatives designated as hedging instruments	$	—	$	22	$	1,749	$	12,475

Effect of derivative instruments on the statement of operations

	Amount of Gain (Loss)
	Recognized in OCI on Derivative						Amount Reclassified from
Derivatives in	(Effective Portion)						Accumulated OCI into Income
Cash Flow	Three Months			Three Months			Three Months		Three Months
Hedging	Ended June			Ended June		Location of Amount Reclassified from	Ended June		Ended June
Relationships	30, 2011			30, 2010		Accumulated OCI into Income	30, 2011		30, 2010
Interest rate swaps	$	5,531		$	4,334	Interest expense, net of amounts capitalized	$	—	$	—
Natural gas swaps		(56	)		177	Other gains (losses), net		—		(89	)
Total	$	5,475		$	4,511	Total	$	—	$	(89	)

	Amount of Gain (Loss)
	Recognized in OCI on Derivative						Amount Reclassified from
Derivatives in	(Effective Portion)						Accumulated OCI into Income
Cash Flow	Six Months		Six Months				Six Months		Six Months
Hedging	Ended June		Ended June			Location of Amount Reclassified from	Ended June		Ended June
Relationships	30, 2011		30, 2010			Accumulated OCI into Income	30, 2011		30, 2011
Interest rate swaps	$	10,698	$	5,598		Interest expense, net of amounts capitalized	$	—	$	—
Natural gas swaps		6		(93	)	Other gains (losses), net		—		(89	)
Total	$	10,704	$	5,505		Total	$	—	$	(89	)

Derivatives Not		Amount of Loss Recognized in Income on Derivative
Designated as		Three Months		Three Months		Six Months		Six Months
Hedging	Location of Loss Recognized in Income on	Ended June 30,		Ended June 30,		Ended June 30,		Ended June 30,
Instruments	Derivatives	2011		2010		2011		2010
Natural gas swaps	Other gains and (losses), net	$	—	$	202	$	—	$	202