Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2013

Asset Retirement Obligation [Abstract]

Schedule Of Asset Retirement Obligations

		December 31,
		2013		2012
Asset retirement obligations at beginning of period	$	60,814	$	42,052
Accretion expense		5,171		4,922
Liabilities incurred		7,730		13,638
Liabilities settled		(2,334)		(1,182)
Revisions of estimated liabilities		1,426		1,384
Asset retirement obligations at end of period		72,807		60,814
Less: current asset retirement obligations		(96)		(702)
Long-term asset retirement obligations	$	72,711	$	60,112