Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2011

Asset Retirement Obligations [Abstract]

Schedule Of Asset Retirement Obligations

		December 31,
		2011		2010
Asset retirement obligations at beginning of period	$	28,052	$	17,372
Accretion expense		3,088		2,099
Liabilities incurred		10,878		8,564
Liabilities settled		(3)		(17)
Revisions of estimated liabilities		37		34
Asset retirement obligations at end of period		42,052		28,052
Less: current asset retirement obligations		-		-
Long-term asset retirement obligations	$	42,052	$	28,052