Summary of Significant Accounting Policies (Details 4) (USD $) In Thousands	12 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax, Beginning Balance	$ (321)	$ (53)	$ (971)
Accumulated Other Comprehensive Income (Loss), Defined Benefit Pension and Other Postretirement Plans, Net of Tax, Beginning Balance	1,357	1,942	2,493
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax, Beginning Balance	49,869	51,162	126,639
Accumulated other comprehensive income, Beginning Balance	50,905	53,051	128,161
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax, Ending Balance	112,864	49,869	51,162
Accumulated other comprehensive income, Ending Balance	113,898	50,905	53,051
Accumulated Other Comprehensive Income (Loss), Defined Benefit Pension and Other Postretirement Plans, Net of Tax, Ending Balance	2,188	1,357	1,942
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax, Ending Balance	(1,154)	(321)	(53)
Amortization of gain on post-retirement medical, dental and vision plan	831	(585)	(551)
Unrealized (loss) gain on cash flow hedges	(833)	(268)	918
Foreign currency translation adjustments	62,995	(1,293)	(75,477)
Total comprehensive income (loss)	$ 62,993	$ (2,146)	$ (75,110)