Supplementary Data Accrued Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Accrued Liabilities [Abstract]
Salaries, benefits and related expenses	$ 333.2	$ 502.4
Acquisition obligations	72.5	50.1
Office and related expenses	43.0	51.0
Interest	16.7	17.3
Restructuring and other reorganization-related	2.8	3.3
Other	152.4	136.2
Total accrued liabilities	$ 620.6	$ 760.3