XML 41 R23.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Asset Retirement Obligations | 12 Months Ended
--- | ---
Dec. 31, 2024
Asset Retirement Obligation [Abstract] |
Asset Retirement Obligations | We have recognized asset retirement obligations associated with various legal obligations including costs to remove and dispose of certain construction materials located within many of our facilities (including our JV facilities), certain costs to retire pipeline, removal costs for certain underground storage tanks, removal of certain pipelines known to contain PCB contamination, closure costs for certain sites including ash ponds, solid waste management units and a landfill, as well as some other nominal asset retirement obligations. We also have an obligation associated with the decommissioning of our two hydro facilities located in Indiana. These hydro facilities have an indeterminate life, and as such, no asset retirement obligation has been recorded. During the fourth quarter of 2024, we continued to evaluate the applicability of revisions to the EPA rule for disposal of CCRs, which was announced in May 2024. As a result, we recorded an increase of $149.7 million based on initial assessments of estimated costs to comply with the EPA rule for certain sites. Additional costs will be recorded if they become probable and estimable. These costs are expected to be recoverable through existing and future depreciation rates. See Note 19, "Other Commitments and Contingencies - D. Environmental Matters," for additional information on the legacy CCR rule. Changes in our liability for asset retirement obligations for the years 2024 and 2023 are presented in the table below:
(in millions) | 2024 |  | 2023
Beginning Balance | $ | 553.0 |  |  | $ | 513.5 |
Accretion recorded as a regulatory asset/liability | 25.3 |  |  | 20.0 |
Additions | 189.9 |  |  | 23.5 |
Settlements | (72.5) |  |  | (41.6) |
Change in estimated cash flows | 87.5 |  |  | 37.6 |
Ending Balance | $ | 783.2 |  |  | $ | 553.0 |
Certain non-legal costs of removal not yet incurred but have been, and continue to be, included in depreciation rates and collected in the customer rates of the rate-regulated subsidiaries are classified as "Regulatory liabilities" on the Consolidated Balance Sheets.

X
- References No definition available. + Details
Name: | us-gaap_AssetRetirementObligationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for an asset retirement obligation and the associated long-lived asset. An asset retirement obligation is a legal obligation associated with the disposal or retirement from service of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481850/410-20-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org/410-20/tableOfContent Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 20 -Topic 410 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481850/410-20-50-2 + Details
Name: | us-gaap_AssetRetirementObligationDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration