Revenue Recognition (Schedule Of Disaggregation Of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Revenue	$ 448,756	$ 397,032	$ 1,148,031	$ 980,597
Water [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	223,617	211,762	423,750	404,284
Revenue	224,181	212,183	424,929	405,114
Water [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	149,542	144,415	280,830	277,272
Water [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	41,025	37,967	76,145	71,155
Water [Member] | Fire Protection [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	9,547	8,919	18,740	17,964
Water [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	7,604	7,747	14,785	14,736
Water [Member] | Other Water [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	15,899	12,714	33,250	23,157
Water [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,109	421	1,724	830
Water [Member] | Other And Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	(545)		(545)
Wastewater [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	41,565	32,554	76,967	64,104
Revenue	41,404	32,504	76,779	64,100
Wastewater [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	30,653	24,312	57,148	48,673
Wastewater [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	6,973	5,268	13,038	10,263
Wastewater [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	432	410	776	854
Wastewater [Member] | Other Wastewater [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	3,507	2,564	6,005	4,314
Wastewater [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	(161)	(50)	(188)	(4)
Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	168,165	142,891	614,553	486,046
Revenue	168,341	142,886	614,553	486,252
Natural Gas [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	95,942	83,760	381,048	297,953
Natural Gas [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	18,853	14,850	75,893	55,871
Natural Gas [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	957	521	2,799	1,478
Natural Gas [Member] | Gas Transportation [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	40,573	37,789	119,747	115,593
Natural Gas [Member] | Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	11,840	5,971	35,066	15,151
Natural Gas [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	176	(5)		206
Other [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	3,325	3,489	6,240	7,315
Revenue	14,830	9,459	31,770	25,131
Other [Member] | Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	3,325	3,489	6,240	7,315
Other [Member] | Other And Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 11,505	$ 5,970	$ 25,530	$ 17,816