Consolidated Statement of Comprehensive Income Parentheticals (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Other Comprehensive Income (Loss), Tax, Parenthetical Disclosures [Abstract]
Unrealized Gain (Loss) on Securities, Tax	$ 0.5	$ (1.1)	$ 0.7	$ (0.3)
Unrealized Loss on Derivatives, Tax	(0.1)	(0.2)	(0.2)	(0.2)
Defined Benefit Pension and Other Postretirement Benefit Plans, Tax	$ 0.2	$ 0.3	$ 0.9	$ 0.8