Derivatives and Hedging Activities (Details Textual)	Oct. 31, 2011 USD ($)	Jul. 31, 2011 USD ($)	Oct. 31, 2011 Designated as Hedging Instrument [Member] USD ($)	Jul. 31, 2011 Designated as Hedging Instrument [Member] USD ($)	Oct. 31, 2011 Nondesignated [Member] USD ($)	Jul. 31, 2011 Nondesignated [Member] USD ($)	Oct. 31, 2011 Foreign Exchange Contract [Member] Other Current Liabilities [Member] Designated as Hedging Instrument [Member] USD ($)	Jul. 31, 2011 Foreign Exchange Contract [Member] Other Current Liabilities [Member] Designated as Hedging Instrument [Member] USD ($)	Oct. 31, 2011 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] Other Current Liabilities [Member] Designated as Hedging Instrument [Member] USD ($)	Jul. 31, 2011 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] Other Current Liabilities [Member] Designated as Hedging Instrument [Member] USD ($)	Oct. 31, 2011 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] Other Current Liabilities [Member] Nondesignated [Member] USD ($)	Jul. 31, 2011 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] Other Current Liabilities [Member] Nondesignated [Member] USD ($)	Oct. 31, 2011 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] Prepaid expenses and other current assets [Member] Designated as Hedging Instrument [Member] USD ($)	Jul. 31, 2011 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] Prepaid expenses and other current assets [Member] Designated as Hedging Instrument [Member] USD ($)	Oct. 31, 2011 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] Prepaid expenses and other current assets [Member] Nondesignated [Member] USD ($)	Jul. 31, 2011 Foreign Exchange Contract [Member] Cash Flow Hedging [Member] Prepaid expenses and other current assets [Member] Nondesignated [Member] USD ($)	May 13, 2010 Senior Unsecured Notes [Member] EUR (€)
Debt Instrument [Line Items]
Private Placement in Euros/Dollars																	€ 75,000,000
Additional Derivatives and Hedging Activities (Textual) [Abstract]
Forward exchange contracts designated as cash flow hedges			296,000	16,000	21,000	3,000							296,000	16,000	21,000	3,000
Forward exchange contracts designated as hedge instruments			108,969,000	114,110,000	1,000	2,000	2,656,000	5,295,000	188,000	830,000	1,000	2,000
Derivatives and Hedging Activities (Textual) [Abstract]
Notional amount of outstanding forward exchange contracts	56,938,000	80,807,000
Unrealized losses on foreign currency cash flow hedges expected to be reclassified to earnings within the next twelve months	252,000	1,535,000
Outstanding forward foreign exchange contracts including certain specific contracts	25,288,000	30,519,000
Outstanding forward foreign exchange contracts	$ 31,650,000	$ 50,000,000