Stock-Based Compensation (Summary Of Compensation Costs) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation within operations and maintenance expenses	$ 139	$ 94	$ 380	$ 395
Income tax benefit	26	27	95	113
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation within operations and maintenance expenses	1,676	1,285	5,018	4,216
Income tax benefit	309	365	1,261	1,191
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation within operations and maintenance expenses	702	724	2,206	2,089
Income tax benefit	126	205	554	586
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation within operations and maintenance expenses	13	11	38	117
Income tax benefit	4	3	11	34
Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation within operations and maintenance expenses	165	175	522	525
Income tax benefit	$ 48	$ 51	$ 151	$ 152

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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