Asset Retirement Obligations (Tables)

3 Months Ended

Mar. 31, 2012

Asset Retirement Obligations [Abstract]

Asset Retirement Obligation Rollforward Analysis

The following table presents the reconciliation of the beginning and ending aggregate carrying amounts of short-term and long-term legal obligations associated with the retirement of property, plant and equipment for the three-month periods ended March 31, 2012 and 2011 (in thousands):

	Three Months Ended
	March 31,
	2012			2011
Carrying Amount at Beginning of Period	$	587,084		$	498,288
Liabilities Incurred		10,873			5,959
Liabilities Settled (1)		(25,347	)		(14,078	)
Accretion		7,751			6,166
Revisions		5			748
Foreign Currency Translations		3,078			2,158
Carrying Amount at End of Period	$	583,444		$	499,241
Current Portion	$	42,457		$	33,315
Noncurrent Portion	$	540,987		$	465,926

(1)      Includes settlements related to asset sales.