Rate Activity (Details) - USD ($)				9 Months Ended
	Oct. 26, 2020	May 24, 2019	Apr. 24, 2019	Sep. 30, 2020
Water And Wastewater Rates [Line Items]
Base rate increase (decrease)			$ 76,493,000
Base rate increase designed to increase total operating revenues on an annual basis			$ 29,493,000
Increase in water and waster rates			7.50%
Distribution system improvement charges reset level upon new base rates			$ 0
Indiana And Ohio [Member]
Water And Wastewater Rates [Line Items]
Base rate increase (decrease)				$ 1,054,000
Illinois And North Carolina [Member]
Water And Wastewater Rates [Line Items]
Base rate increase (decrease)				$ 12,280,000
Pennsylvania [Member]
Water And Wastewater Rates [Line Items]
Base rate increase (decrease)		$ 47,000,000
Subsequent Event [Member] | North Carolina [Member]
Water And Wastewater Rates [Line Items]
Base rate increase (decrease)	$ 3,426,000