Asset Retirement Obligations (Tables)

9 Months Ended

Sep. 30, 2013

Asset Retirement Obligations [Abstract]

Schedule Of Change In Asset Retirement Obligation

		Nine Months Ended
		September 30, 2013
Beginning of period	$	126,991
Assumed in acquisition		10,676
Revisions to previous estimates		3,934
Liabilities incurred		229
Liabilities settled		(4,659)
Accretion expense		5,411
End of period	$	142,582
Less: Current portion of asset retirement obligations		(1,729)
Asset retirement obligations - non-current	$	140,853