Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Sales	$ 2,176,689	$ 2,035,518	$ 4,272,839	$ 3,937,421
Cost of goods sold, including warehouse and distribution expenses	1,049,510	976,727	2,048,081	1,891,671
Gross profit	1,127,179	1,058,791	2,224,758	2,045,750
Selling, general and administrative expenses	702,118	673,023	1,381,071	1,309,609
Operating income	425,061	385,768	843,687	736,141
Other income (expense):
Interest expense	(18,701)	(14,319)	(33,522)	(28,721)
Interest income	1,193	577	1,945	1,157
Other, net	1,241	182	2,258	1,295
Total other expense	(16,267)	(13,560)	(29,319)	(26,269)
Income before income taxes	408,794	372,208	814,368	709,872
Provision for income taxes	151,000	138,700	301,200	263,500
Net income	$ 257,794	$ 233,508	$ 513,168	$ 446,372
Earnings per share-basic:
Earnings per share - basic	$ 2.69	$ 2.32	$ 5.31	$ 4.42
Weighted-average common shares outstanding - basic	95,967	100,547	96,554	101,078
Earnings per share-assuming dilution:
Earnings per share - assuming dilution	$ 2.65	$ 2.29	$ 5.24	$ 4.35
Weighted-average common shares outstanding - assuming dilution	97,282	102,109	97,911	102,684