Consolidated Statement of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Comprehensive Income (Loss) [Abstract]
Net Income	$ 25.2	$ 29.4	$ 71.7	$ 68.2
Other Comprehensive Income (Loss) [Abstract]
Unrealized Gain (Loss) on Securities, Net of Income Taxes of $(0.3), $0.5, $(0.2) and $0.7	(0.5)	0.5	(0.4)	1.0
Unrealized Gain (Loss) on Derivatives, Net of Income Taxes of $(0.1), $(0.1), $- and $(0.2)	(0.1)	0	0	(0.2)
Defined Benefit Pension and Other Postretirement Benefit Plans, Net of Income Taxes of $0.3, $0.2, $0.8 and $0.9	0.3	0.4	1.1	1.4
Total Other Comprehensive Income (Loss)	(0.3)	0.9	0.7	2.2
Comprehensive Income	$ 24.9	$ 30.3	$ 72.4	$ 70.4