Consolidated Statements Of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 18,467.5	$ 18,032.4	$ 16,240.5
Cost of sales	15,257.4	14,992.5	13,533.6
Gross profit	3,210.1	3,039.9	2,706.9
Selling and administrative expenses	2,030.9	1,906.3	1,719.6
Operating income	1,179.2	1,133.6	987.3
Interest expense, net	(154.9)	(159.4)	(148.6)
Other (expense) income, net	(22.0)	(24.5)	1.8
Income before income taxes	1,002.3	949.7	840.5
Income tax expense	(213.8)	(212.9)	(197.5)
Net income	$ 788.5	$ 736.8	$ 643.0
Net income per common share:
Basic (in dollars per share)	$ 5.53	$ 5.08	$ 4.26
Diluted (in dollars per share)	$ 5.45	$ 4.99	$ 4.19
Weighted-average common shares outstanding:
Basic (in shares)	142.6	145.1	150.9
Diluted (in shares)	144.8	147.8	153.6