Revenue Recognition (Schedule Of Disaggregation Of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Revenue	$ 436,700	$ 448,756	$ 1,163,150	$ 1,148,031
Water [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	244,286	223,617	459,452	423,750
Revenue	245,053	224,181	460,621	424,929
Water [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	167,121	149,542	314,373	280,830
Water [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	46,774	41,025	87,728	76,145
Water [Member] | Fire Protection [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	10,185	9,547	20,444	18,740
Water [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	8,289	7,604	16,146	14,785
Water [Member] | Other Water [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	11,917	15,899	20,761	33,250
Water [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	767	1,109	1,169	1,724
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	45,941	41,565	91,334	76,967
Revenue	45,970	41,404	91,543	76,779
Wastewater [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	34,046	30,653	67,536	57,148
Wastewater [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	8,656	6,973	17,247	13,038
Wastewater [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	509	432	1,087	776
Wastewater [Member] | Other Wastewater [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,730	3,507	5,464	6,005
Wastewater [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	29	(161)	209	(188)
Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	138,951	168,165	578,857	614,553
Revenue	138,983	168,341	580,278	614,553
Natural Gas [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	76,476	95,942	368,706	381,048
Natural Gas [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	16,297	18,853	81,454	75,893
Natural Gas [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	471	957	2,260	2,799
Natural Gas [Member] | Gas Transportation [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	34,862	40,573	102,515	119,747
Natural Gas [Member] | Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	10,845	11,840	23,922	35,066
Natural Gas [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	32	176	1,421
Other [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,649	3,325	8,808	6,240
Revenue	6,694	14,830	30,708	31,770
Other [Member] | Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,649	3,325	8,808	6,240
Other [Member] | Other And Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 4,045	$ 11,505	$ 21,900	$ 25,530