Consolidated Statements of Income and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Impairment charges	$ 13,525		$ 3,466
Amortization of intangible assets	11,037	11,135	10,262
Income from continuing operations before income taxes	221,972	165,388	132,337
Income taxes	70,296	53,953	40,690
Net income from continuing operations	151,676	111,435	91,647
Income from discontinued operations, net of income taxes	1,186	10,304	14,626
Net income	152,862	121,739	106,273
Earnings per common share from continuing operations:
Basic	$ 2.86	$ 2.07	$ 1.66
Diluted	$ 2.86	$ 2.07	$ 1.66
Earnings per common share from discontinued operations:
Basic	$ 0.02	$ 0.19	$ 0.26
Diluted	$ 0.02	$ 0.19	$ 0.26
Earnings per common share:
Basic	$ 2.88	$ 2.26	$ 1.92
Diluted	$ 2.88	$ 2.26	$ 1.92
Net income	152,862	121,739	106,273
Unrealized appreciation on investments, net of tax effects of $23, $6 and $158	38	7	257
Comprehensive income	152,900	121,746	106,530
Continuing Operations
Net sales	3,241,795	2,639,798	2,340,442
Cost of products sold	2,817,256	2,320,268	2,041,506
Gross profit	424,539	319,530	298,936
Selling, general and administrative expenses	194,650	148,260	160,532
Impairment charges	2,000		2,036
Amortization of intangible assets	10,460	10,651	9,595
Interest income	2,628	3,744	3,880
Interest expense	6	47	1
Other income, net	$ 1,921	$ 1,072	$ 1,685