Restructuring and Other Reorganization-Related Charges (Reversals), net (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restructuring and other Reorganization Related Charges (Reversals), net
Restructuring Charges	$ 60.6	$ (0.2)	$ 0.3	$ (0.1)	$ (0.1)	$ (0.4)	$ (0.7)	$ 0	$ 60.6	$ (1.2)	$ 1.0
Prior Year Restructuring Plans
Restructuring and other Reorganization Related Charges (Reversals), net
Restructuring Charges									(0.6)
Restructuring Reserve	1.3								1.3
2013 Restructuring Plan
Restructuring and other Reorganization Related Charges (Reversals), net
Restructuring Charges									61.2
Non-cash items									(0.5)
Cash Payments									(11.0)
Foreign Currency Translation Adjustment									1.2
Restructuring Reserve	50.9								50.9
Restructuring and Related Cost, Number of Positions Eliminated									541
Employee Severance
Restructuring and other Reorganization Related Charges (Reversals), net
Restructuring Charges									55.9	0	(0.1)
Employee Severance | 2013 Restructuring Plan
Restructuring and other Reorganization Related Charges (Reversals), net
Restructuring Charges									55.9
Non-cash items									0
Cash Payments									(10.6)
Foreign Currency Translation Adjustment									1.2
Restructuring Reserve	46.5								46.5
Real Estate
Restructuring and other Reorganization Related Charges (Reversals), net
Restructuring Charges									4.2	(1.1)	1.3
Real Estate | 2013 Restructuring Plan
Restructuring and other Reorganization Related Charges (Reversals), net
Restructuring Charges									4.8
Non-cash items									(0.5)
Cash Payments									(0.4)
Foreign Currency Translation Adjustment									0
Restructuring Reserve	3.9								3.9
Other Restructuring
Restructuring and other Reorganization Related Charges (Reversals), net
Restructuring Charges									0.5	(0.1)	(0.2)
Other Restructuring | 2013 Restructuring Plan
Restructuring and other Reorganization Related Charges (Reversals), net
Restructuring Charges									0.5
Non-cash items									0
Cash Payments									0
Foreign Currency Translation Adjustment									0
Restructuring Reserve	0.5								0.5
IAN | 2013 Restructuring Plan
Restructuring and other Reorganization Related Charges (Reversals), net
Restructuring Charges									56.0
CMG
Restructuring and other Reorganization Related Charges (Reversals), net
Restructuring Charges									$ 5.0