Description Of Business (Details)	3 Months Ended
	Mar. 31, 2014 customer mi
Description Of Business [Line Items]
Electrification area	400
Number of wholesale customers	2
Percentage of employees belonging to unions	70.00%
Hotel Employees and Restaurant Employees [Member]
Description Of Business [Line Items]
Expiration date of collective bargaining agreements	Jun. 30, 2016
International Brotherhood of Electrical Workers [Member]
Description Of Business [Line Items]
Number of collective bargaining agreements	3
Expiration date of collective bargaining agreements	Jun. 30, 2017