Basis Of Presentation (Details) - customer		9 Months Ended
	Mar. 16, 2020	Sep. 30, 2020
Customer Relationships [Member]
Basis Of Presentation [Line Items]
Useful life		15 years
Noncompete Agreements [Member]
Basis Of Presentation [Line Items]
Useful life		5 years
Peoples Gas Acquisition [Member]
Basis Of Presentation [Line Items]
Number of customers	747,000