Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]
Sales	$ 1,727,943	$ 1,585,009
Cost of goods sold, including warehouse and distribution expenses	850,227	786,346
Gross profit	877,716	798,663
Selling, general and administrative expenses	590,596	547,579
Operating income	287,120	251,084
Other income (expense):
Interest expense	(13,409)	(11,400)
Interest income	631	477
Other, net	618	468
Total other expense	(12,160)	(10,455)
Income before income taxes	274,960	240,629
Provision for income taxes	101,100	86,300
Net income	$ 173,860	$ 154,329
Earnings per share-basic:
Earnings per share - basic	$ 1.64	$ 1.38
Weighted-average common shares outstanding - basic	106,191	111,557
Earnings per share-assuming dilution:
Earnings per share - assuming dilution	$ 1.61	$ 1.36
Weighted-average common shares outstanding - assuming dilution	108,070	113,396