Leases (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Leases, Rent Expense, Net [Abstract]
Minimum Rental Expense	$ 33.2	$ 31.5	$ 35.6
Less: Sublease Rental Income	(2.5)	(2.1)	(2.4)
Net Rental Exense	30.7	29.4	33.2
Future Minimum Lease Payments, Capital and Operating Leases
Capital Leases, Future Minimum Payments Due, 2013	1.9
Capital Leases, Future Minimum Payments Due, 2014	1.4
Capital Leases, Future Minimum Payments Due, 2015	1.0
Capital Leases, Future Minimum Payments Due, 2016	1.0
Capital Leases, Future Minimum Payments Due, 2017	0.2
Capital Leases, Future Minimum Payments Due, 2018 and Thereafter	0
Capital Leases, Total Future Payments	5.5
Less: Imputed Interest	(0.6)
Present Value of Minimum Capital Lease Payments	4.9
Operating Leases, Future Minimum Payments Due, 2013	28.3
Operating Leases, Future Minimum Payments Due, 2014	23.5
Operating Leases, Future Minimum Payments Due, 2015	14.5
Operating Leases, Future Minimum Payments Due, 2016	12.2
Operating Leases, Future Minimum Payments Due, 2017	10.1
Operating Leases, Future Minimum Payments Due, 2018 and Thereafter	7.8
Operating Leases, Total Future Payments	96.4
Capital Leases, Future Minimum Sublease Rentals	$ 6.5
Office Space [Member] | Minimum [Member]
Operating Leased Assets [Line Items]
Operating Lease, Term	1 year
Office Space [Member] | Maximum [Member]
Operating Leased Assets [Line Items]
Operating Lease, Term	10 years
Equipment [Member] | Minimum [Member]
Operating Leased Assets [Line Items]
Operating Lease, Term	1 year
Equipment [Member] | Maximum [Member]
Operating Leased Assets [Line Items]
Operating Lease, Term	5 years