COMMITMENTS AND CONTINGENCIES - ENVIRONMENTAL MATTERS (Details) $ in Millions	1 Months Ended				6 Months Ended	66 Months Ended
	May 31, 2023 performance_obligations MW	Apr. 30, 2023 MMBTU	Jan. 31, 2023 micrograms	Dec. 31, 2020 micrograms performance_obligations	Jun. 30, 2023 USD ($) performance_obligations MW generating_units	Jun. 30, 2023 USD ($) MW	Mar. 31, 2023 performance_obligations	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Manufactured gas plant remediation
Regulatory assets | $					$ 3,247.5	$ 3,247.5		$ 3,306.9
Environmental remediation costs
Manufactured gas plant remediation
Regulatory assets | $					$ 582.7	$ 582.7		610.7
Cross State Air Pollution Rule - Good Neighbor Plan | Electric | Maximum
Air quality
RICE Unit megawatts | MW					25	25
Mercury and Air Toxics Standards | Electric
Air quality
Current level of particulate matter in pounds per million british thermal unit | MMBTU		0.03
EPA proposed lower limit for particulate matter | MMBTU		0.01
Even lower level of particulate matter that the EPA is seeking opinions on | MMBTU		0.006
National Ambient Air Quality Standards | Electric
Air quality
The EPA issued a draft policy assessment in support of revisiting the decision to make no changes to the 2015 Ozone standards | performance_obligations							0
Number of revisions necessary to meet the 2012 standard for particulate matter | performance_obligations				0
Current number of micrograms per cubic meter that particulate matter needs to be below				12
Current level of micrograms per cubic meter under 24-hour standard that fine particulate matter needs to be below				35
Lowest limit that will cause nonattainment			10
National Ambient Air Quality Standards | Electric | Maximum
Air quality
Proposed primary (health-based) annual standard			10
The EPA is taking comments on this full range of micrograms per cubic meter			11
New possible number of micrograms per cubic meter that particulate matter may be lowered to			11
National Ambient Air Quality Standards | Electric | Minimum
Air quality
Proposed primary (health-based) annual standard			9
The EPA is taking comments on this full range of micrograms per cubic meter			8
New possible number of micrograms per cubic meter that particulate matter may be lowered to			10
Climate Change | Electric
Air quality
Number of applicable GHG performance standards for coal plants | performance_obligations	0
Percent capacity factor that if combined cycle natural gas plants are above it causes the rule to be highly dependent on hydrogen or carbon capture	50.00%
Number of applicable limits that apply to simple cycle natural gas-fired combustion turbines that have less than a 20% capacity factor | performance_obligations	0
Percent capacity factor for simple cycle natural gas fired combustion turbines that there are no applicable limits if the capacity factor is less than this.	20.00%
Rules that are being proposed for natural gas-fired stationary combustion turbines | performance_obligations	1
Number of subcategories of stationary combustion turbine unit annual capacity factors that the proposed rule will be broken up into | performance_obligations	3
Capacity of coal-fired generation retired, in megawatts | MW						1,900
Capacity of fossil-fueled generation to be retired by the end of 2026, in megawatts | MW					1,500
Company goal for percentage of carbon emissions reduction below 2005 levels by the end of 2025					60.00%
Company goal for percentage of carbon emissions reduction below 2005 levels by the end of 2030					80.00%
Climate Change | Electric | Maximum
Air quality
RICE Unit megawatts | MW	25
Clean Water Act Cooling Water Intake Structure Rule | Electric
Water quality
Number of generating units that may be retired | generating_units					4
Steam Electric Effluent Limitation Guidelines | Electric
Water quality
Number of new ELG rule requirements that affect our electric utilities | performance_obligations					2
Capital investment to achieve required discharge limits | $					$ 105.0	$ 105.0
Steam Electric Effluent Limitation Guidelines | Electric | OCPP Units 7 and 8 | WE
Water quality
Capital investment to achieve required discharge limits | $									$ 8.0
Steam Electric Effluent Limitation Guidelines | Electric | Weston Unit 3 | WPS
Water quality
Capital investment to achieve required discharge limits | $					8.0	8.0
Steam Electric Effluent Limitation Guidelines | Electric | Elm Road Generating Station | WE
Water quality
Capital investment to achieve required discharge limits | $					89.0	89.0			$ 89.0
Manufactured Gas Plant Remediation | Natural gas
Manufactured gas plant remediation
Reserves for future environmental remediation | $					475.8	475.8		499.6
Manufactured Gas Plant Remediation | Natural gas | Environmental remediation costs
Manufactured gas plant remediation
Regulatory assets | $					$ 582.7	$ 582.7		$ 610.7