Asset Retirement Obligations (Tables)

6 Months Ended

Jun. 30, 2015

Asset Retirement Obligation [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 six-month periods ended June 30, 2015 and 2014 (in thousands):

	Six Months Ended   June 30,
	2015			2014
Carrying Amount at Beginning of Period	$	752,718		$	761,898
Liabilities Incurred	19,990			54,819
Liabilities Settled (1)	(9,891		)	(25,478		)
Accretion	15,815			23,346
Revisions	18,156			13,859
Foreign Currency Translations	(1,009		)	2,506
Carrying Amount at End of Period	$	795,779		$	830,950
Current Portion	$	10,993		$	28,498
Noncurrent Portion	$	784,786		$	802,452

(1) Includes settlements related to asset sales.