Condensed Consolidated Statements Of Operations (USD $)
In Thousands, except Share data, unless otherwise specified
 3 Months Ended 9 Months Ended
Apr. 30, 2012
Apr. 30, 2011
Apr. 30, 2012
Apr. 30, 2011
Condensed Consolidated Statements Of Operations [Abstract]        
Net sales $ 926,458 $ 852,059 $ 2,196,428 $ 1,984,970
Cost of products sold 816,988 743,575 1,952,600 1,752,265
Gross profit 109,470 108,484 243,828 232,705
Selling, general and administrative expenses 46,963 50,386 121,668 136,019
Impairment of trademarks   1,430   3,466
Amortization of intangible assets 2,756 2,734 8,380 7,298
Gain on involuntary conversion   1,818   8,651
Interest income 936 949 2,996 2,950
Interest expense 101 45 371 152
Other income 633 662 958 1,114
Income before income taxes 61,219 57,318 117,363 98,485
Income taxes 19,878 17,310 39,984 29,101
Net income $ 41,341 $ 40,008 $ 77,379 $ 69,384
Weighted average common shares outstanding:        
Basic 52,879,877 55,829,122 54,162,411 55,079,700
Diluted 52,970,357 55,941,389 54,212,663 55,185,181
Earnings per common share:        
Basic $ 0.78 $ 0.72 $ 1.43 $ 1.26
Diluted $ 0.78 $ 0.72 $ 1.43 $ 1.26
Regular dividends declared and paid per common share: $ 0.15 $ 0.10 $ 0.45 $ 0.30