Supplementary Data Accrued Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Accounts Payable, Current [Abstract]
Salaries, benefits and related expenses	$ 356.4	$ 510.6
Office and related expenses	46.1	51.5
Acquisition obligations	65.6	88.1
Interest	17.5	18.3
Restructuring and other reorganization-related	4.0	5.5
Other	114.2	122.0
Accrued liabilities, current	$ 603.8	$ 796.0