Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2021

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Asset Retirement Obligations

The following table presents the changes in our net asset retirement obligations (in millions):

	December 31,
	2021		2020
Net asset retirement obligations at January 1	$	35.1	$	34.8
Liabilities acquired(1)	—		0.3
Liabilities incurred	—		0.3
Liabilities settled	(0.4)		(0.8)
Accretion expense	1.9		1.9
Other(2)	(0.4)		(1.4)
Net asset retirement obligations at December 31(3)	$	36.2	$	35.1

(1)Primarily relates to the NGL Asset Acquisition in 2020. See Note 3 for a further discussion of these acquisitions.

(2)Relates to obligations associated with the abandonment and dismantlement of our Marcellus West Union compressor assets in 2021 as further discussed in Note 2 and the obligations included in the sale of our Fayetteville assets in 2020 as further discussed in Note 3.

(3)Includes $1.4 million and $1.0 million of current ARO liabilities at December 31, 2021 and 2020.