Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Sales	$ 2,290,829	$ 2,176,689	$ 4,447,088	$ 4,272,839
Cost of goods sold, including warehouse and distribution expenses	1,090,767	1,049,510	2,115,879	2,048,081
Gross profit	1,200,062	1,127,179	2,331,209	2,224,758
Selling, general and administrative expenses	742,617	702,118	1,470,607	1,381,071
Operating income	457,445	425,061	860,602	843,687
Other income (expense):
Interest expense	(20,827)	(18,701)	(40,231)	(33,522)
Interest income	470	1,193	1,176	1,945
Other, net	(762)	1,241	3	2,258
Total other expense	(21,119)	(16,267)	(39,052)	(29,319)
Income before income taxes	436,326	408,794	821,550	814,368
Provision for income taxes	153,505	151,000	273,795	301,200
Net income	$ 282,821	$ 257,794	$ 547,755	$ 513,168
Earnings per share-basic:
Earnings per share - basic	$ 3.14	$ 2.69	$ 6.02	$ 5.31
Weighted-average common shares outstanding - basic	90,030	95,967	91,012	96,554
Earnings per share-assuming dilution:
Earnings per share - assuming dilution	$ 3.10	$ 2.65	$ 5.93	$ 5.24
Weighted-average common shares outstanding - assuming dilution	91,299	97,282	92,347	97,911