Income Taxes (Schedule Of Reasons For Differences Between Statutory Federal Income Tax Rate To Income Before Income Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Abstract]
Computed Federal tax expense at statutory rate	$ 44,420	$ 37,447	$ 89,828
Decrease in Federal tax expense related to an income tax accounting change for qualifying utility asset improvement costs	(48,518)	(44,089)	(69,325)
State income taxes, net of Federal tax benefit	(3,616)	(4,964)	(3,743)
Increase in tax expense for depreciation expense to be recovered in future rates	347	328	199
Stock-based compensation	(167)	(414)	(595)
Deduction for Essential Utilities common dividends paid under employee benefit plan	(315)	(312)	(455)
Amortization of deferred investment tax credits	(361)	(373)	(376)
Impact of Federal rate change and amortization of excess deferred income tax	(6,323)	(313)	3,141
Other, net	1,516	(979)	(1,760)
Total tax expense	$ (13,017)	$ (13,669)	$ 16,914