Revenue Recognition (Schedule Of Disaggregation Of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Revenue	$ 434,618	$ 361,860	$ 1,582,649	$ 1,342,457
Water [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	253,969	222,187	677,719	626,472
Revenue	255,183	222,714	680,112	627,829
Water [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	173,798	148,247	454,628	425,519
Water [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	49,026	42,318	125,171	113,473
Water [Member] | Fire Protection [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	9,934	8,866	28,674	26,830
Water [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	9,291	8,217	24,076	22,954
Water [Member] | Other Water [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	11,920	14,539	45,170	37,696
Water [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	669	527	2,393	1,357
Water [Member] | Other And Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	545
Wastewater [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	44,216	33,882	121,183	97,986
Revenue	44,276	33,904	121,055	98,004
Wastewater [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	32,806	25,147	89,954	73,820
Wastewater [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	8,769	5,839	21,807	16,102
Wastewater [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	466	401	1,242	1,256
Wastewater [Member] | Other Wastewater [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,175	2,495	8,180	6,808
Wastewater [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	60	22	(128)	18
Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	119,721	95,069	734,274	581,114
Revenue	119,721	95,069	734,274	581,320
Natural Gas [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	65,631	49,838	446,679	347,790
Natural Gas [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	15,180	9,534	91,073	65,404
Natural Gas [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	990	415	3,789	1,894
Natural Gas [Member] | Gas Transportation [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	26,824	27,794	146,571	143,387
Natural Gas [Member] | Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	11,096	7,488	46,162	22,639
Natural Gas [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue				206
Other [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,362	3,241	8,602	10,556
Revenue	15,438	10,173	47,208	35,304
Other [Member] | Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,362	3,241	8,602	10,556
Other [Member] | Other And Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 13,076	$ 6,932	$ 38,606	$ 24,748