Stock-Based Compensation (Summary Of Compensation Costs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation within operations and maintenance expenses	$ 106	$ 2,443
Income tax benefit	26	612
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation within operations and maintenance expenses	846	681
Income tax benefit	211	171
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation within operations and maintenance expenses	131	77
Income tax benefit	33	19
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation within operations and maintenance expenses	12	12
Income tax benefit	$ 3	3
Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation within operations and maintenance expenses		210
Income tax benefit		$ 59