Summary of Effects of Recently Adopted Accounting Pronouncements to Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Accounts payable and accrued expenses	$ 1,024.5	$ 831.9	$ 738.7	$ 725.1	$ 662.1	$ 659.1
Income taxes payable	12.7	7.5			4.3	5.0
Retained earnings	4,786.0	4,237.4	$ 3,845.6	3,832.6	3,477.3	3,479.0
Accumulated other comprehensive loss	$ (77.6)	$ (66.7)		$ (53.6)	(37.0)	$ (36.4)
New Revenue Standard
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Accounts payable and accrued expenses					3.0
Income taxes payable					(0.7)
Retained earnings					(2.3)
Accumulated other comprehensive loss					0.0
New Tax Reform
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Accounts payable and accrued expenses					0.0
Income taxes payable					0.0
Retained earnings					0.6
Accumulated other comprehensive loss					$ (0.6)