Revenue (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Accounts Receivable, Less Allowance	$ 2,088.9	$ 2,018.8	$ 2,104.6
Contract Assets (Current)	50.5	51.7
Contract Assets (Long-Term)	178.2	215.4
Contract Liabilities (Current)	242.8	277.1
Contract Liabilities (Long-Term)	$ 10.4	$ 17.9