Regulatory Environment - PGL and NSG UEA Rider (Details) - Illinois Commerce Commission (ICC) $ in Millions	1 Months Ended
	May 31, 2023 USD ($)	Dec. 31, 2024 USD ($) Assurance
2018 Annual Uncollectible Expense Adjustment Rider Reconciliation | PGL
Public Utilities, General Disclosures
Refunds required to customers	$ 15.4
Refund period	9 months
2018 Annual Uncollectible Expense Adjustment Rider Reconciliation | NSG
Public Utilities, General Disclosures
Refunds required to customers	$ 0.7
Refund period	9 months
Uncollectible Expense Adjustment Rider Reconciliation - Open Years
Public Utilities, General Disclosures
Amount of assurance that UEA rider costs will be recoverable | Assurance		0
Minimum annual costs included in UEA rider		$ 10.0
Maximum annual costs included in UEA rider		$ 40.0