Financial Instruments and Risk Management (Impact of Cash Flow Hedges on Accumulated Other Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Reclassification of net losses to earnings, net of taxes	$ 1.9	[1]	$ 1.7	[1]	$ 3.9
Treasury Locks [Member]
Balance at Period Start	(5.1)		(6.8)
Reclassification of net losses to earnings, net of taxes	1.9		1.7
Balance at Period End	(3.2)		(5.1)
Net unamortized losses at beginning of year, tax effect	2.7		3.7
Reclassification of net losses to earnings, tax effect	0		1.0
Net unamortized losses at end of year, tax effect	$ 2.7		$ 2.7

[1] Gross amount reclassified to interest expense, and related taxes reclassified to income taxes.