Fair Value (Fair Value Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Money market funds	$ 20.7	$ 26.9
Total Assets	28.5	128.5
Total Liabilities	4.6	3.2
Available-for-sale Securities [Member]
Available-for-sale securities	2.1	1.9
Interest-Rate Swap Agreements [Member]
Derivative Assets	1.0	94.8
Derivative Liabilities	0.6	1.7
Foreign Exchange Forward Contracts [Member]
Derivative Assets	4.7	4.9
Derivative Liabilities	4.0	1.5
Level 1 [Member]
Money market funds	20.7	26.9
Total Assets	22.8	28.8
Total Liabilities	0	0
Level 1 [Member] | Available-for-sale Securities [Member]
Available-for-sale securities	2.1	1.9
Level 1 [Member] | Interest-Rate Swap Agreements [Member]
Derivative Assets	0	0
Derivative Liabilities	0	0
Level 1 [Member] | Foreign Exchange Forward Contracts [Member]
Derivative Assets	0	0
Derivative Liabilities	0	0
Level 2 [Member]
Money market funds	0	0
Total Assets	5.7	99.7
Total Liabilities	4.6	3.2
Level 2 [Member] | Available-for-sale Securities [Member]
Available-for-sale securities	0	0
Level 2 [Member] | Interest-Rate Swap Agreements [Member]
Derivative Assets	1.0	94.8
Derivative Liabilities	0.6	1.7
Level 2 [Member] | Foreign Exchange Forward Contracts [Member]
Derivative Assets	4.7	4.9
Derivative Liabilities	$ 4.0	$ 1.5