Segment Information (Details) (USD $) In Thousands	3 Months Ended								12 Months Ended
	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2010	Jul. 31, 2010	Apr. 30, 2010	Jan. 31, 2010	Oct. 31, 2009	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Intersegment information
Revenues from external customers	$ 343,104	$ 337,896	$ 329,009	$ 329,588	$ 322,894	$ 321,887	$ 295,829	$ 318,486	$ 1,339,597	$ 1,259,096	$ 1,208,702
Depreciation and amortization expense									48,827	53,022	54,851
Segment Profit									291,926	266,459	248,902
Assets	1,861,505				1,746,531				1,861,505	1,746,531	1,583,267
Expenditures for property, plant and equipment									20,532	26,296	24,027
Americas [Member]
Intersegment information
Revenues from external customers									577,428	551,185	534,440
Intersegment revenues									41,638	43,136	45,853
Depreciation and amortization expense									15,682	21,142	22,022
Segment Profit									145,516	125,169	114,404
Assets	735,003				754,753				735,003	754,753	703,559
Expenditures for property, plant and equipment									8,212	8,502	8,422
Europe [Member]
Intersegment information
Revenues from external customers									404,955	380,121	367,156
Intersegment revenues									3,054	4,456	4,310
Depreciation and amortization expense									8,147	8,088	8,467
Segment Profit									112,047	103,316	99,875
Assets	333,977				313,204				333,977	313,204	298,717
Expenditures for property, plant and equipment									2,626	1,535	3,326
Asia-Pacific [Member]
Intersegment information
Revenues from external customers									357,214	327,790	307,106
Intersegment revenues									24,500	18,188	18,534
Depreciation and amortization expense									15,515	15,749	15,957
Segment Profit									50,105	52,105	42,575
Assets	389,465				362,653				389,465	362,653	341,605
Expenditures for property, plant and equipment									8,620	9,946	5,848
Total Region [Member]
Intersegment information
Revenues from external customers									1,339,597	1,259,096	1,208,702
Intersegment revenues									69,192	65,780	68,697
Depreciation and amortization expense									39,344	44,979	46,446
Segment Profit									307,668	280,590	256,854
Assets	1,458,445				1,430,610				1,458,445	1,430,610	1,343,881
Expenditures for property, plant and equipment									19,458	19,983	17,596
Corporate and Eliminations [Member]
Intersegment information
Intersegment revenues									(69,192)	(65,780)	(68,697)
Depreciation and amortization expense									9,483	8,043	8,405
Segment Profit									(15,742)	(14,131)	(7,952)
Assets	403,060				315,921				403,060	315,921	239,386
Expenditures for property, plant and equipment									$ 1,074	$ 6,313	$ 6,431