Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Sales	$ 2,410,608	$ 2,282,681
Cost of goods sold, including warehouse and distribution expenses	1,131,318	1,081,423
Gross profit	1,279,290	1,201,258
Selling, general and administrative expenses	834,504	778,412
Operating income	444,786	422,846
Other income (expense):
Interest expense	(34,291)	(28,217)
Interest income	554	572
Other, net	3,103	205
Total other expense	(30,634)	(27,440)
Income before income taxes	414,152	395,406
Provision for income taxes	93,000	90,500
Net income	$ 321,152	$ 304,906
Earnings per share-basic:
Earnings per share - basic	$ 4.09	$ 3.65
Weighted-average common shares outstanding - basic	78,484	83,530
Earnings per share-assuming dilution:
Earnings per share - assuming dilution	$ 4.05	$ 3.61
Weighted-average common shares outstanding - assuming dilution	79,297	84,523