Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Sales	$ 1,901,903	$ 1,727,943
Cost of goods sold, including warehouse and distribution expenses	914,944	850,227
Gross profit	986,959	877,716
Selling, general and administrative expenses	636,586	590,596
Operating income	350,373	287,120
Other income (expense):
Interest expense	(14,402)	(13,409)
Interest income	580	631
Other, net	1,113	618
Total other expense	(12,709)	(12,160)
Income before income taxes	337,664	274,960
Provision for income taxes	124,800	101,100
Net income	$ 212,864	$ 173,860
Earnings per share-basic:
Earnings per share - basic	$ 2.09	$ 1.64
Weighted-average common shares outstanding - basic	101,612	106,191
Earnings per share-assuming dilution:
Earnings per share - assuming dilution	$ 2.06	$ 1.61
Weighted-average common shares outstanding - assuming dilution	103,257	108,070