XML 75 R24.htm IDEA: XBRL DOCUMENT v3.25.0.1
ASSET RETIREMENT OBLIGATIONS
 12 Months Ended
Dec. 31, 2024
Asset Retirement Obligation Disclosure [Abstract]  
ASSET RETIREMENT OBLIGATIONS ASSET RETIREMENT OBLIGATIONS
Asset retirement obligations (AROs) are legal obligations associated with the retirement of long-lived assets resulting from the acquisition, construction, development and/or normal use of the underlying assets, including legal obligations for land reclamation. Recognition of a liability for an ARO is required in the period in which it is incurred at its estimated fair value. The associated asset retirement costs are capitalized as part of the carrying amount of the underlying asset and depreciated over the estimated useful life of the asset. The liability is accreted through charges to operating expenses. If the ARO is settled for a value other than the carrying amount of the liability, we recognize a gain or loss on settlement.
For the years ended December 31, ARO operating costs related to accretion of the liabilities and depreciation of the assets are as follows:
in millions202420232022
Accretion$14.7 $13.9 $14.1 
Depreciation12.5 9.0 9.4 
Total ARO operating costs$27.2 $22.9 $23.5 
ARO operating costs are reported in cost of revenues. AROs are reported within other noncurrent liabilities in our accompanying Consolidated Balance Sheets.
Reconciliations of the carrying amounts of our AROs for the years ended December 31 are as follows:
in millions20242023
ARO balance at beginning of year$324.1 $311.3 
Liabilities incurred42.3 0.0 
Liabilities settled(19.1)(9.9)
Accretion expense14.7 13.9 
Revisions, net65.4 8.8 
ARO balance at end of year$427.4 $324.1 
ARO liabilities incurred during 2024 relate to those assumed in 2024 acquisitions (see Note 19). ARO revisions during 2024 primarily related to cost adjustments for a number of aggregates properties in California that are being reclaimed for alternative uses post mining.