Regulatory Environment - PGL and NSG 2023 Rate Case (Details) - Illinois Commerce Commission (ICC) - 2023 Rate Case - Subsequent event $ in Millions	Jan. 06, 2023 USD ($)
PGL
Public Utilities, General Disclosures
Requested rate increase	$ 194.7
Requested rate increase (as a percent)	13.00%
Requested return on equity (as a percent)	9.90%
Requested equity capital structure (as a percent)	54.00%
NSG
Public Utilities, General Disclosures
Requested rate increase	$ 18.7
Requested rate increase (as a percent)	7.80%
Requested return on equity (as a percent)	9.90%
Requested equity capital structure (as a percent)	54.00%