Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2011

Fair Value Measurements [Abstract]

Recurring Fair Value Measurements

	December 31, 2011
	Level 2			Level 3			Total
	(In thousands)
Financial assets (liabilities):
Commodity derivatives:
Assets	$	9,698		$	34,321		$	44,019
Liabilities		(9,518	)		(706	)		(10,224	)
	$	180		$	33,615		$	33,795

	December 31, 2010
	Level 2			Level 3			Total
	(In thousands)
Financial assets (liabilities):
Interest rate swaps	$	0		$	(1,614	)	$	(1,614	)
Commodity derivatives:
Assets	$	0		$	11,546		$	11,546
Liabilities		(19,954	)		(678	)		(20,632	)
	$	(19,954	)	$	10,868		$	(9,086	)

Reconciliations Of Level 3 Fair Value Measurements

	Net Derivatives
	For the Year Ended December 31, 2011						For the Year Ended December 31, 2010
	Interest Rate Swaps			Commodity Swaps			Interest Rate Swaps			Commodity Swaps
	(In thousands)
Beginning of period	$	(1,614	)	$	10,868		$	(1,948	)	$	19,948
Total gains or losses (realized and unrealized):
Included in earnings (loss) (1)		(1,734	)		20,086			(1,218	)		64,470
Included in other comprehensive income (loss)		1,614			22,503			334			(10,116	)
Settlements		1,734			(19,842	)		1,218			(63,434	)
End of period	$	0		$	33,615		$	(1,614	)	$	10,868
Total gains (losses) for the period included in earnings attributable to the change in unrealized gain (loss) relating to assets still held as of December 31, 2011 and 2010	$	0		$	244		$	0		$	1,036

(1) Interest rate swaps and commodity sales swaps and collars are reported in the consolidated statements of operations in interest expense and revenues, respectively.