Derivatives and Risk Management (Tables)

9 Months Ended

Sep. 30, 2011

Derivatives And Risk Management [Abstract]

Balance Sheet Classification of Derivative Financial Instruments

	Derivative Assets
	September 30, 2011		December 31, 2010
	Balance Sheet Classification	Fair Value	Balance Sheet Classification	Fair Value
	(in thousands)
Derivatives designated as hedging instruments:
Fixed and floating price swaps	Hedging asset	$        213,334	Hedging asset	$          81,797
Costless-collars	Hedging asset	101,988	Hedging asset	48,582
Fixed and floating price swaps	Other assets	72,797	Other assets	5,086
Costless-collars	Other assets	23,668	Other assets	72,827
Total derivatives designated as hedging instruments		$        411,787		$        208,292
Derivatives not designated as hedging instruments:
Basis swaps	Hedging asset	$               224	Hedging asset	$                 33
Basis swaps	Other assets	558	Other assets	0
Total derivatives not designated as hedging instruments		$               782		$                 33
Total derivative assets		$        412,569		$        208,325
	Derivative Liabilities
	September 30, 2011		December 31, 2010
	Balance Sheet Classification	Fair Value	Balance Sheet Classification	Fair Value
	(in thousands)
Derivatives designated as hedging instruments:
Fixed and floating price swaps	Hedging liability	$            6,533	Hedging liability	$            1,774
Costless-collars	Hedging liability	604	Hedging liability	3,903
Fixed and floating price swaps	Long-term hedging liability	2,507	Long-term hedging liability	22,334
Costless-collars	Long-term hedging liability	1,094	Long-term hedging liability	17,854
Total derivatives designated as hedging instruments		$          10,738		$          45,865
Derivatives not designated as hedging instruments:
Basis swaps	Hedging liability	$             1,934	Hedging liability	$            2,008
Basis swaps	Long-term hedging liability	981	Long-term hedging liability	0
Total derivatives not designated as hedging instruments		$             2,915		$            2,008
Total derivative liabilities		$           13,653		$          47,873

Cash Flow Hedges, Volumes of Natural Gas Production (in Bcf)

Year:	Fixed price swaps	Costless-collars
2011	64.7	15.6
2012	185.9	80.5
2013	185.2	0

Before Tax Effect of Cash Flow Hedges on Consolidated Financial Statements

		Gain Recognized in Other Comprehensive Income (Effective Portion)
		For the three months ended		For the nine months ended
		September 30,		September 30,
Derivative Instrument		2011	2010	2011	2010
		(in thousands)
Fixed price swaps		$   230,783	$     75,864	$    360,362	$     166,398
Costless-collars		$     48,315	$     84,750	$      65,144	$     140,282
	Classification of Gain Reclassified from Accumulated Other	Gain Reclassified from Accumulated Other Comprehensive Income into Earnings (Effective Portion)
	Comprehensive Income	For the three months ended		For the nine months ended
	into Earnings	September 30,		September 30,
Derivative Instrument	(Effective Portion)	2011	2010	2011	2010
		(in thousands)
Fixed price swaps	Gas Sales	$     67,125	$     65,761	$    145,662	$     144,015
Costless-collars	Gas Sales	$     13,918	$     16,073	$     40,978	$     50,635
		Gain (Loss) Recognized in Earnings (Ineffective Portion)
	Classification of Gain (Loss)	For the three months ended		For the nine months ended
	Recognized in Earnings	September 30,		September 30,
Derivative Instrument	(Ineffective Portion)	2011	2010	2011	2010
		(in thousands)
Fixed price swaps	Gas Sales	$     (1,754)	$    (258)	$        (755)	$    (3,924)
Costless-collars	Gas Sales	$        (826)	$    (157)	$          252	$    (1,577)

Before Tax Effect of Basis Swaps Not Qualifying for Hedge Accounting

		Unrealized Gain (Loss) Recognized in Earnings
	Income Statement	For the three months ended		For the nine months ended
	Classification	September 30,		September 30,
Derivative Instrument	of Unrealized Gain (Loss)	2011	2010	2011	2010
		(in thousands)
Basis swaps	Gas Sales	$        (1,967)	$      1,620	$       (159)	$      9,496
		Realized Gain (Loss) Recognized in Earnings
	Income Statement	For the three months ended		For the nine months ended
	Classification	September 30,		September 30,
Derivative Instrument	of Realized Gain (Loss)	2011	2010	2011	2010
		(in thousands)
Basis swaps	Gas Sales	$        (22)	$    (2,580)	$    (2,377)	$    (9,811)