Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2012

Fair Value Measurements [Abstract]

Schedule Of Fair Value Of Financial Assets And Liabilities By Level

As of June 30, 2012		Total		Level 1		Level 2		Level 3
Assets from commodity derivative instruments	$	177,078	$	-	$	177,078	$	-
	$	177,078	$	-	$	177,078	$	-
Liabilities from commodity derivative instruments	$	3,622	$	-	$	3,622	$	-
Liabilities from interest rate derivative instruments		26,242		-		26,242		-
	$	29,864	$	-	$	29,864	$	-
As of December 31, 2011		Total		Level 1		Level 2		Level 3
Assets from commodity derivative instruments	$	103,233	$	-	$	103,233	$	-
Assets from interest rate derivative instruments		20		-		20		-
	$	103,253	$	-	$	103,253	$	-
Liabilities from commodity derivative instruments	$	2,502	$	-	$	2,502	$	-
Liabilities from interest rate derivative instruments		23,973		-		23,973		-
	$	26,475	$	-	$	26,475	$	-