REGULATORY ENVIRONMENT - PGL AND NSG 2023 RATE CASE (Details) - Illinois Commerce Commission (ICC) $ in Millions	1 Months Ended
	Jan. 31, 2023 USD ($)
PGL
Public Utilities, General Disclosures [Line Items]
Requested rate increase	$ 194.7
Requested rate increase (as a percent)	13.00%
Requested return on equity (as a percent)	9.90%
Requested common equity component average (as a percent)	54.00%
NSG
Public Utilities, General Disclosures [Line Items]
Requested rate increase	$ 18.7
Requested rate increase (as a percent)	7.80%
Requested return on equity (as a percent)	9.90%
Requested common equity component average (as a percent)	54.00%