Asset Retirement Obligations (Tables)

6 Months Ended

Jun. 30, 2021

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, 2021 and 2020 (in millions):

	Six Months Ended June 30,
	2021		2020
Carrying Amount at January 1	$	1,217	$	1,111
Liabilities Incurred	40		17
Liabilities Settled (1)	(55)		(25)
Accretion	22		23
Revisions	3		20
Carrying Amount at June 30	$	1,227	$	1,146
Current Portion	$	47	$	39
Noncurrent Portion	$	1,180	$	1,107

(1)Includes settlements related to asset sales.