Leases - Net Rental Expense (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Leases [Abstract]
Noncancelable, Minimum rental expense	$ 115.2	$ 102.1	$ 89.7
Noncancelable, Contingent rental expense	2.3	2.4	3.7
Noncancelable, Sublease rental expense	(0.9)	(0.9)	(1.6)
Other rental expense	77.9	74.6	69.3
Net rental expense	$ 194.5	$ 178.2	$ 161.1