Common Equity Automatic Dividend Reinvestment and Stock Purchase Plan (Details) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Automatic Dividend Reinvestment and Stock Purchase Plan [Member]	Sep. 30, 2014 Automatic Dividend Reinvestment and Stock Purchase Plan [Member]
Stock Issued During Period, Shares, Dividend Reinvestment Plan and Stock Purchase Plan			90,151	280,113
Proceeds From Issuance of Shares Under Dividend Reinvestment Plan And Stock Purchase Plan	$ 10.1	$ 10.8	$ 3.3	$ 10.1
Shares Held in Reserve Related to Dividend Reinvestment Plan and Stock Purchase Plan			3,565,390	3,565,390