Reportable Business Segments, Reconciliation of Segment Operating Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Reconciliation of segment operating income to consolidated income before income taxes
Segment operating income	$ 326.3	$ 294.8	$ 866.1	$ 815.7
Interest expense	(18.1)	(17.0)	(54.2)	(51.1)
Other income, net	2.3	4.2	5.0	12.5
Stock-based compensation expense	(12.2)	(11.8)	(35.5)	(32.1)
Acquisition-related expenses	(6.3)		(36.6)	(5.7)
Other operating expenses	(11.0)	(11.0)	(32.6)	(33.0)
Income before income taxes	310.5	282.0	816.9	777.1
Operating Segment
Reconciliation of segment operating income to consolidated income before income taxes
Segment operating income	$ 355.8	$ 317.6	$ 970.8	$ 886.5