Derivatives and Risk Management (Tables)

3 Months Ended

Mar. 31, 2012

Derivatives And Risk Management [Abstract]

Balance Sheet Classification of Derivative Financial Instruments

	Derivative Assets
	March 31, 2012		December 31, 2011
	Balance Sheet Classification	Fair Value	Balance Sheet Classification	Fair Value
	(in thousands)
Derivatives designated as hedging instruments:
Fixed and floating price swaps	Hedging asset	$        437,974	Hedging asset	$        333,479
Costless-collars	Hedging asset	180,101	Hedging asset	179,080
Fixed and floating price swaps	Other assets	211,439	Other assets	201,081
Total derivatives designated as hedging instruments		$        829,514		$        713,640
Derivatives not designated as hedging instruments:
Basis swaps	Hedging asset	$             2,636	Hedging asset	$             1,906
Basis swaps	Other assets	2,179	Other assets	1,797
Total derivatives not designated as hedging instruments		$            4,815		$            3,703
Total derivative assets		$        834,329		$        717,343
	Derivative Liabilities
	March 31, 2012		December 31, 2011
	Balance Sheet Classification	Fair Value	Balance Sheet Classification	Fair Value
	(in thousands)
Derivatives designated as hedging instruments:
Fixed and floating price swaps	Hedging liability	$          14,341	Hedging liability	$          11,849
Costless-collars	Hedging liability	28	Hedging liability	209
Total derivatives designated as hedging instruments		$          14,369		$          12,058
Derivatives not designated as hedging instruments:
Basis swaps	Hedging liability	$               209	Hedging liability	$               400
Basis swaps	Long-term hedging liability	136	Long-term hedging liability	55
Total derivatives not designated as hedging instruments		$               345		$               455
Total derivative liabilities		$          14,714		$          12,513

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

Year:	Fixed price swaps	Costless-collars
2012	139.2	60.5
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
		March 31,
Derivative Instrument		2012	2011
		(in thousands)
Fixed price swaps		$    218,957	$         9,069
Costless-collars		$      56,511	$         1,954
	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
	into Earnings	March 31,
Derivative Instrument	(Effective Portion)	2012	2011
		(in thousands)
Fixed price swaps	Gas Sales	$    106,311	$       36,801
Costless-collars	Gas Sales	$      55,310	$       15,098
		Gain (Loss) Recognized in Earnings (Ineffective Portion)
	Classification of Gain (Loss)	For the three months ended
	Recognized in Earnings	March 31,
Derivative Instrument	(Ineffective Portion)	2012	2011
		(in thousands)
Fixed price swaps	Gas Sales	$        4,299	$       (2,067)
Costless-collars	Gas Sales	$           911	$        2,161

Before Tax Effect of Basis Swaps Not Qualifying for Hedge Accounting

		Unrealized Gain Recognized in Earnings
	Income Statement	For the three months ended
	Classification	March 31,
Derivative Instrument	of Unrealized Gain	2012	2011
		(in thousands)
Basis swaps	Gas Sales	$        1,223	$          906
		Realized Gain (Loss) Recognized in Earnings
	Income Statement	For the three months ended
	Classification	March 31,
Derivative Instrument	of Realized Gain (Loss)	2012	2011
		(in thousands)
Basis swaps	Gas Sales	$        1,018	$       (2,256)