Reportable Business Segments, Reconciliation of Segment Operating Income to Consolidated Income Before Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information
Operating income	$ 476.2	$ 357.4	$ 941.0	$ 674.3
Stock-based compensation expense	(20.0)	(16.6)	(39.0)	(32.0)
Acquisition-related expenses	(55.4)	0.0	(55.4)	0.0
Other operating expenses	(15.0)	(13.9)	(29.0)	(27.7)
Interest expense	(29.1)	(30.2)	(57.7)	(59.0)
Other (expense) income, net	0.0	1.3	(0.4)	2.4
Income from continuing operations before income taxes	447.1	328.5	882.9	617.7
Operating Segment
Segment Reporting Information
Operating income	$ 566.6	$ 387.9	$ 1,064.4	$ 734.0