Rate and Regulatory Matters (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Regulatory Liabilities [Line Items]
Deferred income tax benefits	$ (5,075)	$ (2,760)
Middlesex [Member] | New Jersey Board Of Public Utilities [Member]
Regulatory Liabilities [Line Items]
Additional annual costs	100
Tidewater [Member] | Delaware Public Service Commission Member
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues	$ 500
Corporate tax rate	3.35%
Base rate amount	$ 1,000
Line of credit	700
Pinelands Water Company [Member]
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues	200
Pinelands Wastewater [Member]
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues	500
Twin Lakes [Member] | Pennsylvania Public Utilities Commissio [Member]
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues	$ 200