Commitments and Contingencies - Environmental Requirements - Water and Waste (Details) - Federal Coal Ash Regulation $ in Millions	Jun. 30, 2022 USD ($) Plan
Site Contingency [Line Items]
Number of sites where regulated ash units will still be in operation at a specified date	5
Number of sites where statistically significant increases over established groundwater standards exist | Plan	4
Number of sites where corrective action options are being evaluated for locations with statistically significant increases above background concentrations | Plan	2
Estimated cost to remediate groundwater sampling results	$ 35
Estimated cost of construction of an alternative collection and treatment system	25
EPA Penalty	1
Maximum [Member]
Site Contingency [Line Items]
Cost of Beneficial Use Coal Ash Project	40
Minimum [Member]
Site Contingency [Line Items]
Cost of Beneficial Use Coal Ash Project	$ 30