Revenue Recognition (Schedule Of Disaggregation Of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenue	$ 411,255	$ 434,618	$ 1,574,405	$ 1,582,649
Regulated Water [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	258,367	253,969	717,819	677,719
Revenue	258,801	255,183	719,422	680,112
Regulated Water [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	173,331	173,798	487,704	454,628
Regulated Water [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	49,699	49,026	137,427	125,171
Regulated Water [Member] | Fire Protection [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	10,350	9,934	30,794	28,674
Regulated Water [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	9,438	9,291	25,584	24,076
Regulated Water [Member] | Other Water [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	15,549	11,920	36,310	45,170
Regulated Water [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	434	669	1,603	2,393
Regulated 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	48,819	44,216	140,153	121,183
Revenue	48,892	44,276	140,435	121,055
Wastewater [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	36,096	32,806	103,632	89,954
Wastewater [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	9,396	8,769	26,643	21,807
Wastewater [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	500	466	1,587	1,242
Wastewater [Member] | Other Wastewater [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,827	2,175	8,291	8,180
Wastewater [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue	73	60	282	(128)
Regulated Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	94,798	119,721	673,655	734,274
Revenue	94,798	119,721	675,076	734,274
Regulated Natural Gas [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	46,501	65,631	415,207	446,679
Regulated Natural Gas [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	9,577	15,180	91,031	91,073
Regulated Natural Gas [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	353	990	2,613	3,789
Regulated Natural Gas [Member] | Gas Transportation [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	26,636	26,824	129,151	146,571
Regulated Natural Gas [Member] | Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	11,731	11,096	35,653	46,162
Regulated Natural Gas [Member] | Alternative Revenue Program [Member]
Disaggregation of Revenue [Line Items]
Revenue			1,421
Other [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,898	2,362	11,706	8,602
Revenue	8,764	15,438	39,472	47,208
Other [Member] | Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,898	2,362	11,706	8,602
Other [Member] | Other And Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 5,866	$ 13,076	$ 27,766	$ 38,606