XML 64 R50.htm IDEA: XBRL DOCUMENT
v3.20.4

Asset Retirement Obligations (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2020
Asset Retirement Obligation Disclosure [Abstract] |
Schedule of changes to asset retirement obligations | The following table shows changes to our AROs during the years ended December 31:
(in millions) |  | 2020 |  | 2019 |  | 2018
Balance as of January 1 |  | $ | 483.5 |  |  | $ | 461.4 |  |  | $ | 573.7 |  |
Accretion |  | 20.7 |  |  | 22.1 |  |  | 28.0 |  |
Additions and revisions to estimated cash flows |  | 39.7 |  | (1) | 39.1 |  | (2) | (104.5) |  | (3)
Liabilities settled |  | (30.4) |  |  | (39.1) |  |  | (35.8) |  |
Balance as of December 31 |  | $ | 513.5 |  |  | $ | 483.5 |  |  | $ | 461.4 |  |
(1) AROs increased $39.3 million in 2020, primarily due to new natural gas distribution lines being placed into service at PGL. Also in 2020, AROs increased by $8.5 million as a result of AROs being recorded for the legal requirement to dismantle, at retirement, the Two Creeks solar generation project. AROs decreased $9.2 million due to revisions made to estimated cash flows for the abatement of asbestos at WE. (2) AROs increased $40.1 million in 2019, primarily due to new natural gas distribution lines being placed into service at PGL. Also in 2019, AROs increased $10.7 million as a result of AROs being recorded for the legal requirement to dismantle, at retirement, certain non-utility wind generation projects. AROs decreased $7.3 million due to revisions made to estimated cash flows for the abatement of asbestos at WE. (3) AROs decreased $127.3 million in 2018 due to revisions made to estimated cash flows primarily for changes in the cost to retire natural gas distribution pipe at PGL. Also in 2018, AROs increased $10.7 million as a result of revisions made to estimated cash flows for the abatement of asbestos at WPS's Pulliam power plant, and a $10.9 million ARO was recorded for the legal requirement to dismantle, at retirement, certain wind generation projects.

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

X
- Definition Tabular disclosure of the changes in carrying amount of a liability for asset retirement obligations, for changes such as new obligations, changes in estimates of existing obligations, spending on existing obligations, property dispositions, and foreign currency translation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13201-110859 + Details
Name: | us-gaap_ScheduleOfChangeInAssetRetirementObligationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration