ASSET RETIREMENT OBLIGATIONS (Tables)

3 Months Ended

Mar. 31, 2021

Asset Retirement Obligation [Abstract]

Summary Of Asset Retirement Obligations

The following is a summary of our asset retirement obligations:

	(In Millions)
	March 31, 2021		December 31, 2020
Asset retirement obligations1	$	310	$	342
Less: current portion	12		7
Long-term asset retirement obligations	$	298	$	335
1 Includes $158 million and $190 million related to our active operations as of March 31, 2021 and December 31, 2020, respectively.

Schedule of Change in Asset Retirement Obligation

The following is a roll forward of our asset retirement obligation liability:

	(In Millions)
	2021		2020
Asset retirement obligation as of January 1	$	342	$	165
Increase (decrease) from Acquisitions	(34)		14
Accretion expense	3		2
Remediation payments	(1)		—
Asset retirement obligation as of March 31	$	310	$	181