Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2012

Fair Value Measurements [Abstract]

Assets And Liabilities Measured At Fair Value On A Recurring Basis

	March 31, 2012										December 31, 2011
	Level 1		Level 2			Level 3		Total			Level 1		Level 2			Level 3		Total
	(In thousands)
Assets:
Derivative instruments	$	—	$	63,497		$	—	$	63,497		$	—	$	61,073		$	—	$	61,073
Liabilities:
Derivative instruments		—		(33,732	)		—		(33,732	)		—		(23,792	)		—		(23,792	)
Total	$	—	$	29,765		$	—	$	29,765		$	—	$	37,281		$	—	$	37,281