Commitments and Contingencies Environmental Requirements - Water and Waste (Details) $ in Millions	Sep. 30, 2023 USD ($) sites Period
Site Contingency [Line Items]
Number of sites that will excavate and process ash for beneficial use | sites	2
Number of sites where investigation and feasibility studies for additional corrective action related to offsite groundwater are ongoing | sites	3
Federal Coal Ash Regulation
Site Contingency [Line Items]
Number of sites where regulated ash units will still be in operation at a specified date | Period	8
Federal Coal Ash Regulation | PSCo
Site Contingency [Line Items]
Estimated cost to remediate groundwater sampling results	$ 40
Federal Coal Ash Regulation | PSCo | Maximum [Member]
Site Contingency [Line Items]
Cost of Beneficial Use Coal Ash Project	45
Federal Clean Water Act Section 316 (b) | Capital Addition Purchase Commitments
Site Contingency [Line Items]
Liability for estimated cost to comply with regulation	$ 50