Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Sales	$ 2,156,259	$ 2,096,150
Cost of goods sold, including warehouse and distribution expenses	1,025,112	998,571
Gross profit	1,131,147	1,097,579
Selling, general and administrative expenses	727,990	678,953
Operating income	403,157	418,626
Other income (expense):
Interest expense	(19,404)	(14,821)
Interest income	706	752
Other, net	765	1,017
Total other expense	(17,933)	(13,052)
Income before income taxes	385,224	405,574
Provision for income taxes	120,290	150,200
Net income	$ 264,934	$ 255,374
Earnings per share-basic:
Earnings per share - basic	$ 2.88	$ 2.63
Weighted-average common shares outstanding - basic	92,001	97,140
Earnings per share-assuming dilution:
Earnings per share - assuming dilution	$ 2.83	$ 2.59
Weighted-average common shares outstanding - assuming dilution	93,495	98,537