XML 56 R41.htm IDEA: XBRL DOCUMENT v3.22.0.1
Asset Retirement Obligations (Tables)
 12 Months Ended
Dec. 31, 2021
Asset Retirement Obligation [Abstract]  
Changes to Asset Retirement Obligation

The following table describes changes to the asset retirement obligation liability (dollars in millions):

 

 

 

Year Ended December 31,

 

 

 

2021

 

 

2020

 

Asset retirement obligation at beginning of period

 

$

31.8

 

 

$

27.8

 

Accretion expense

 

 

1.2

 

 

 

1.3

 

Liabilities incurred

 

 

1.0

 

 

 

—

 

Revisions in estimated cash flows (a)

 

 

(4.5

)

 

 

3.5

 

Payments

 

 

(0.1

)

 

 

(0.8

)

Asset retirement obligation at end of period

 

$

29.4

 

 

$

31.8

 
(a)
For 2021 and 2020, primarily consists of an asset retirement adjustment of $4.2 million and $4.5 million, respectively, related to the San Lorenzo, California facility closure.