Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Sales	$ 2,220,955	$ 2,080,201	$ 6,493,794	$ 6,017,622
Cost of goods sold, including warehouse and distribution expenses	1,050,929	990,947	3,099,010	2,882,618
Gross profit	1,170,026	1,089,254	3,394,784	3,135,004
Selling, general and administrative expenses	722,217	673,994	2,103,288	1,983,603
Operating income	447,809	415,260	1,291,496	1,151,401
Other income (expense):
Interest expense	(18,706)	(14,296)	(52,228)	(43,017)
Interest income	1,227	551	3,172	1,708
Other, net	1,563	(647)	3,821	648
Total other expense	(15,916)	(14,392)	(45,235)	(40,661)
Income before income taxes	431,893	400,868	1,246,261	1,110,740
Provision for income taxes	153,400	134,600	454,600	398,100
Net income	$ 278,493	$ 266,268	$ 791,661	$ 712,640
Earnings per share-basic:
Earnings per share - basic	$ 2.93	$ 2.68	$ 8.25	$ 7.09
Weighted-average common shares outstanding - basic	94,891	99,270	95,994	100,468
Earnings per share-assuming dilution:
Earnings per share - assuming dilution	$ 2.90	$ 2.64	$ 8.14	$ 6.98
Weighted-average common shares outstanding - assuming dilution	96,120	100,770	97,309	102,041