Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Sales	$ 2,339,830	$ 2,220,955	$ 6,786,918	$ 6,493,794
Cost of goods sold, including warehouse and distribution expenses	1,109,536	1,050,929	3,225,415	3,099,010
Gross profit	1,230,294	1,170,026	3,561,503	3,394,784
Selling, general and administrative expenses	768,331	722,217	2,238,938	2,103,288
Operating income	461,963	447,809	1,322,565	1,291,496
Other income (expense):
Interest expense	(24,324)	(18,706)	(64,555)	(52,228)
Interest income	592	1,227	1,768	3,172
Other, net	1,299	1,563	1,302	3,821
Total other expense	(22,433)	(15,916)	(61,485)	(45,235)
Income before income taxes	439,530	431,893	1,261,080	1,246,261
Provision for income taxes	155,796	153,400	429,591	454,600
Net income	$ 283,734	$ 278,493	$ 831,489	$ 791,661
Earnings per share-basic:
Earnings per share - basic	$ 3.26	$ 2.93	$ 9.28	$ 8.25
Weighted-average common shares outstanding - basic	86,947	94,891	89,641	95,994
Earnings per share-assuming dilution:
Earnings per share - assuming dilution	$ 3.22	$ 2.90	$ 9.15	$ 8.14
Weighted-average common shares outstanding - assuming dilution	88,025	96,120	90,869	97,309