Leases (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Rent Expense [Abstract]
Rent expense, net	$ 402.4	$ 416.4	$ 411.5
Future Minimum Lease Payments Under Non-Cancelable Operating Leases [Abstract]
Operating Leases, Future Minimum Lease Payments, Gross Rent, 2014	380.4
Operating Leases, Future Minimum Lease Payments, Gross Rent, 2015	268.7
Operating Leases, Future Minimum Lease Payments, Gross Rent, 2016	195.3
Operating Leases, Future Minimum Lease Payments, Gross Rent, 2017	139.1
Operating Leases, Future Minimum Lease Payments, Gross Rent, 2018	111.2
Operating Leases, Future Minimum Lease Payments, Gross Rent, Thereafter	302.9
Operating Leases, Future Minimum Lease Payments, Gross Rent	1,397.6
Operating Leases, Future Minimum Lease Payments, Less Sublease Rent, 2014	8.6
Operating Leases, Future Minimum Lease Payments, Less Sublease Rent, 2015	4.0
Operating Leases, Future Minimum Lease Payments, Less Sublease Rent, 2016	1.6
Operating Leases, Future Minimum Lease Payments, Less Sublease Rent, 2017	1.5
Operating Leases, Future Minimum Lease Payments, Less Sublease Rent, 2018	0.4
Operating Leases, Future Minimum Lease Payments, Less Sublease Rent, Thereafter	0
Operating Leases, Future Minimum Lease Payments, Less Sublease Rent	16.1
Operating Leases, Future Minimum Lease Payments, Net Rent, 2014	371.8
Operating Leases, Future Minimum Lease Payments, Net Rent, 2015	264.7
Operating Leases, Future Minimum Lease Payments, Net Rent, 2016	193.7
Operating Leases, Future Minimum Lease Payments, Net Rent, 2017	137.6
Operating Leases, Future Minimum Lease Payments, Net Rent, 2018	110.8
Operating Leases, Future Minimum Lease Payments, Net Rent, Thereafter	302.9
Operating Leases, Future Minimum Lease Payments, Net Rent	1,381.5
Future Minimum Lease Payments Under Non-Cancelable Capital Leases [Abstract]
Capital Leases, Future Minimum Lease Payments, 2014	22.8
Capital Leases, Future Minimum Lease Payments, 2015	15.7
Capital Leases, Future Minimum Lease Payments, 2016	8.6
Capital Leases, Future Minimum Lease Payments, 2017	4.6
Capital Leases, Future Minimum Lease Payments, 2018	3.3
Capital Leases, Future Minimum Lease Payments, Thereafter	2.4
Capital Leases, Future Minimum Lease Payments, Total minimum lease payments	57.4
Capital Leases, Future Minimum Lease Payments, Less interest component	2.0
Capital Leases, Future Minimum Lease Payments, Present value of minimum lease payments	55.4
Property Under Capital Lease and Capital Lease Obligations [Abstract]
Property under capital lease, Cost	134.0	126.3
Property under capital lease, Accumulated depreciation	(80.5)	(71.3)
Property under capital lease	53.5	55.0
Capital lease obligations, Current	22.2	23.4
Capital lease obligations, Long-term	33.2	33.9
Capital lease obligations	55.4	57.3
Property under capital lease, Depreciation expense	26.4	25.9	25.0
Office [Member]
Rent Expense [Abstract]
Office base rent	379.9	390.5	381.6
Less third party sublease rent	10.6	10.4	12.8
Rent expense, net	369.3	380.1	368.8
Equipment [Member]
Rent Expense [Abstract]
Rent expense, net	$ 33.1	$ 36.3	$ 42.7