Capitalization (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Nov. 30, 2021	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Sep. 30, 2018	Aug. 31, 2018
Schedule of Capitalization [Line Items]
Other long term debt		$ 212.7		$ 212.3
Customer advances for construction		23.0		23.5
Dividend Reinvestment and Common Stock Purchase Plan [Member]
Schedule of Capitalization [Line Items]
Proceeds amount		$ 2.9	$ 0.3
Percentage of discount purchase of common stock in investment plan		3.00%
Number of shares offering for discount		200,000
Dividend Reinvestment and Common Stock Purchase Plan [Member] | Common Stock [Member]
Schedule of Capitalization [Line Items]
Number of shares offering for discount		60,096
New Jersey NJIB Program [Member]
Schedule of Capitalization [Line Items]
Maximum borrowing capacity, construction loan					$ 8.7
Delaware SRF Program [Member]
Schedule of Capitalization [Line Items]
Maximum borrowing capacity, construction loan	$ 5.0
Debt Instrument Maturity Date	Dec. 31, 2044
New Jersey Infrastructure Bank [Member]
Schedule of Capitalization [Line Items]
Maximum borrowing capacity, construction loan						$ 43.5
Tidewater [Member]
Schedule of Capitalization [Line Items]
Maximum borrowing capacity, construction loan		$ 1.3		$ 5.0