Acquisitions (Narrative) (Details) $ in Thousands		1 Months Ended
	Aug. 12, 2022 USD ($) customer	Sep. 30, 2023 USD ($) customer	Jul. 31, 2023 USD ($) customer	Jun. 30, 2023 USD ($) customer	Apr. 30, 2023 USD ($) customer	Mar. 31, 2023 USD ($) customer	Nov. 30, 2022 USD ($) customer	Mar. 31, 2022 USD ($) customer	Oct. 31, 2021 USD ($) customer	Jan. 31, 2021 USD ($) customer	Sep. 30, 2019 USD ($) item customer
Shenandoah Borough [Member]
Business Acquisition [Line Items]
Number of customers			2,900
Total purchase price | $			$ 12,291
La Rue [Member]
Business Acquisition [Line Items]
Number of customers			300
Total purchase price | $			$ 2,253
Southern Oaks Water System [Member]
Business Acquisition [Line Items]
Number of customers			750
Total purchase price | $			$ 3,321
Village of Frankfort [Member]
Business Acquisition [Line Items]
Number of customers			1,400
Total purchase price | $			$ 1,424
Union Rome [Member]
Business Acquisition [Line Items]
Number of customers				4,300
Total purchase price | $				$ 25,547
North Heidelberg Sewer Company [Member]
Business Acquisition [Line Items]
Number of customers						273
Total purchase price | $						$ 136
Oak Brook Illinois [Member] | Water And Wastewater Utility Systems [Member]
Business Acquisition [Line Items]
Number of customers							2,037
Total purchase price | $							$ 12,500
Delaware [Member] | Water Utility System [Member]
Business Acquisition [Line Items]
Number of customers											16,000
Total purchase price | $											$ 276,500
Retail customers											198,000
Number of municipalities | item											42
East Whiteland Township [Member] | Water And Wastewater Utility Systems [Member]
Business Acquisition [Line Items]
Number of customers	4,018
Total purchase price | $	$ 54,374
Lower Makefield Township [Member] | Water And Wastewater Utility Systems [Member]
Business Acquisition [Line Items]
Number of customers								11,323
Total purchase price | $								$ 53,000
Greenville, Pennsylvania [Member] | Water And Wastewater Utility Systems [Member]
Business Acquisition [Line Items]
Number of customers					2,300
Total purchase price | $					$ 18,000
Beaver Falls Pennsylvania [Member] | Water Utility System [Member]
Business Acquisition [Line Items]
Number of customers									7,600
Total purchase price | $									$ 41,250
Pennsylvania [Member] | Water And Wastewater Utility Systems [Member]
Business Acquisition [Line Items]
Number of customers										2,300
Total purchase price | $										$ 17,500
Water And Wastewater Utility Systems [Member] | Glenview, Illinois [Member]
Business Acquisition [Line Items]
Number of customers				225
Total purchase price | $				$ 50
Water And Wastewater Utility Systems [Member] | Greenville, Pennsylvania [Member]
Business Acquisition [Line Items]
Number of customers		3,000
Total purchase price | $		$ 18,000