Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2010	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Intersegment information
Revenues from external customers	$ 322,548	$ 331,629	$ 320,584	$ 349,508	$ 343,104	$ 337,896	$ 329,009	$ 329,588	$ 1,324,269	$ 1,339,597	$ 1,259,096
Depreciation and amortization									43,987	48,827	53,022
Segment profit									285,676	291,926	266,459
Assets	1,607,719				1,861,505				1,607,719	1,861,505	1,746,531
Expenditures for property, plant and equipment									24,147	20,532	26,296
Americas [Member]
Intersegment information
Revenues from external customers									589,925	577,428	551,185
Intersegment revenues									40,440	41,638	43,136
Depreciation and amortization									13,706	15,682	21,142
Segment profit									155,657	145,516	125,169
Assets	708,216				735,003				708,216	735,003	754,753
Expenditures for property, plant and equipment									13,623	8,212	8,502
Europe [Member]
Intersegment information
Revenues from external customers									389,156	404,955	380,121
Intersegment revenues									3,577	3,054	4,456
Depreciation and amortization									7,511	8,147	8,088
Segment profit									105,643	112,047	103,316
Assets	332,936				333,977				332,936	333,977	313,204
Expenditures for property, plant and equipment									3,417	2,626	1,535
Asia-Pacific [Member]
Intersegment information
Revenues from external customers									345,188	357,214	327,790
Intersegment revenues									29,798	24,500	18,188
Depreciation and amortization									16,447	15,515	15,749
Segment profit									31,704	50,105	52,105
Assets	248,965				389,465				248,965	389,465	362,653
Expenditures for property, plant and equipment									7,107	8,620	9,946
Total Region [Member]
Intersegment information
Revenues from external customers									1,324,268	1,339,597	1,259,096
Intersegment revenues									73,815	69,192	65,780
Depreciation and amortization									37,664	39,344	44,979
Segment profit									293,004	307,668	280,590
Assets	1,290,117				1,458,445				1,290,117	1,458,445	1,430,610
Expenditures for property, plant and equipment									24,147	19,458	19,983
Corporate and Eliminations [Member]
Intersegment information
Intersegment revenues									(73,815)	(69,192)	(65,780)
Depreciation and amortization									6,323	9,483	8,043
Segment profit									(7,328)	(15,742)	(14,131)
Assets	317,602				403,060				317,602	403,060	315,921
Expenditures for property, plant and equipment										$ 1,074	$ 6,313