Decommissioning Liabilities (Tables)

6 Months Ended

Jun. 30, 2011

Decommissioning Liabilities [Abstract]

Summary of activity for companys decommissioning liabilities

	Six Months Ended
	June 30,
	2011		2010
Decommissioning liabilities, December 31, 2010 and 2009, respectively	$	117,716	$	—
Liabilities acquired and incurred		—		126,559
Accretion		3,336		3,359
Total decommissioning liabilities, June 30, 2011 and 2010, respectively		121,052		129,918
Less: current portion of decommissioning liabilities at June 30, 2011 and 2010, respectively		17,172		22,232
Long-term decommissioning liabilities, June 30, 2011 and 2010, respectively	$	103,880	$	107,686