Rate and Regulatory Matters (Narrative) (Details) - USD ($) $ in Thousands					1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 02, 2023	Jan. 02, 2022	Nov. 04, 2019	Mar. 01, 2019	Dec. 31, 2021	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Nov. 30, 2021
Regulatory Liabilities [Line Items]
Corporate tax rate				3.35%
Regulatory liabilities					$ 30,400			$ 30,400	$ 31,000
Deferred income tax benefits								$ (10,989)	(13,490)	$ (11,719)
Maximum [Member]
Regulatory Liabilities [Line Items]
Corporate tax rate								35.00%
Minimum [Member]
Regulatory Liabilities [Line Items]
Corporate tax rate								21.00%
Middlesex [Member] | Within 30 Days [Member]
Regulatory Liabilities [Line Items]
Escrow deposit											$ 1,700
Tidewater [Member]
Regulatory Liabilities [Line Items]
Proceeds from net of tax refunds						$ 800
Maturity date								Mar. 31, 2046
Delaware Public Service Commission [Member]
Regulatory Liabilities [Line Items]
Percentage of consumer price index								3.00%
Maturity date								Dec. 31, 2029
Delaware Public Service Commission [Member] | Tidewater [Member]
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues									600
New Jersey Board Of Public Utilities [Member] | Pinelands Wastewater [Member]
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues			$ 500
New Jersey Board Of Public Utilities [Member] | Middlesex [Member]
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues					27,700
Base rate amount					$ 513,500
Return on equity					9.60%
Regulatory liabilities					$ 3,000			$ 3,000	$ 14,900
New Jersey Board Of Public Utilities [Member] | Middlesex [Member] | Scenario Forecast [Member]
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues	$ 7,000
New Jersey Board Of Public Utilities [Member] | Middlesex [Member] | Subsequent Event [Member]
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues		$ 20,700
New Jersey Board Of Public Utilities [Member] | Middlesex [Member]
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues						$ 1,100	$ 600