Revenue Recognition (Schedule Of Disaggregation Of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Revenue	$ 699,275	$ 583,565
Water [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	200,133	192,521
Revenue	200,748	192,930
Water [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	131,288	132,856
Water [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	35,120	33,188
Water [Member] | Fire Protection [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	9,193	9,045
Water [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	7,181	6,989
Water [Member] | Other Water [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	17,351	10,443
Water [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	615	409
Wastewater [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	35,402	31,551
Revenue	35,375	31,597
Wastewater [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	26,495	24,361
Wastewater [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	6,065	4,995
Wastewater [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	344	445
Wastewater [Member] | Other Wastewater [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,498	1,750
Wastewater [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	(27)	46
Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	446,388	343,154
Revenue	446,212	343,365
Natural Gas [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	285,106	214,194
Natural Gas [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	57,040	41,021
Natural Gas [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,842	957
Natural Gas [Member] | Gas Transportation [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	79,174	77,803
Natural Gas [Member] | Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	23,226	9,179
Natural Gas [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	(176)	211
Other [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,915	3,826
Revenue	16,940	15,673
Other [Member] | Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,915	3,826
Other [Member] | Other And Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 14,025	$ 11,847