Segments Of Business (Products And Services) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Products and services	100.00%	100.00%	100.00%
Utility electric operations [Member]
Segment Reporting Information [Line Items]
Products and services	81.00%	82.00%	84.00%
Utility gas operations [Member]
Segment Reporting Information [Line Items]
Products and services	15.00%	14.00%	13.00%
Utility other [Member]
Segment Reporting Information [Line Items]
Products and services	2.00%	2.00%	2.00%
Other [Member]
Segment Reporting Information [Line Items]
Products and services	2.00%	2.00%	1.00%