Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Sales	$ 2,096,150	$ 1,901,903
Cost of goods sold, including warehouse and distribution expenses	998,571	914,944
Gross profit	1,097,579	986,959
Selling, general and administrative expenses	678,953	636,586
Operating income	418,626	350,373
Other income (expense):
Interest expense	(14,821)	(14,402)
Interest income	752	580
Other, net	1,017	1,113
Total other expense	(13,052)	(12,709)
Income before income taxes	405,574	337,664
Provision for income taxes	150,200	124,800
Net income	$ 255,374	$ 212,864
Earnings per share-basic:
Earnings per share - basic	$ 2.63	$ 2.09
Weighted-average common shares outstanding - basic	97,140	101,612
Earnings per share-assuming dilution:
Earnings per share - assuming dilution	$ 2.59	$ 2.06
Weighted-average common shares outstanding - assuming dilution	98,537	103,257