Other Income (Expense) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Other Income (Expense) [Abstract]
AFUDC - Equity	$ 1.8	$ 1.1
Gain on Sale of Available-for-sale Securities	0	0.8
Investments and Other Income	0.2	0.8
Total Other Income	$ 2.0	$ 2.7