Income Taxes - Additional Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Operating Loss Carryforwards [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 32,339
Foreign Net Operating Loss Carryforwards Expiration Dates	five to eight years
State Net Operating Loss Carryforwards Expiration Dates	2014 to 2033
Foreign Tax Credit Carryforward Expiration Dates	2021 to 2023
State Research And Development Tax Credit Carryforward Expiration Dates	2014 to 2028
Valuation Allowance, Deferred Tax Asset, Change in Amount	11,295	1,629
Effective Income Tax Rate Reconciliation, Tax Holidays	0.70%	0.70%	0.90%
Unrecognized Tax Benefits, Interest on Income Taxes Expense	200	539	990
Unrecognized Tax Benefits, Income Tax Penalties Expense	313	855	500
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	2,265	1,986
Unrecognized Tax Benefits, Income Tax Penalties Accrued	2,689	2,840
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	13,934
Unrecognized Tax Benefits Recognized In Other Liabilities	32,759	29,765
Reduction Of Longterm Deferred Income Tax Assets Excluding Interest and Penalties	4,815
Foreign [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	124,325
Other Tax Carryforward, Gross Amount	12,486
Foreign, no expiration date [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	99,666
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	58,827
Other Tax Carryforward, Gross Amount	8,531
Maximum recorded through earnings [Member]
Operating Loss Carryforwards [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties Accrued	$ 3,978
United States, Federal [Member] | Low end of range [Member]
Operating Loss Carryforwards [Line Items]
Open Tax Year	2010
United States, Federal [Member] | High end of range [Member]
Operating Loss Carryforwards [Line Items]
Open Tax Year	2013
FRANCE | Low end of range [Member]
Operating Loss Carryforwards [Line Items]
Open Tax Year	2012
FRANCE | High end of range [Member]
Operating Loss Carryforwards [Line Items]
Open Tax Year	2013
GERMANY | Low end of range [Member]
Operating Loss Carryforwards [Line Items]
Open Tax Year	2006
GERMANY | High end of range [Member]
Operating Loss Carryforwards [Line Items]
Open Tax Year	2013
UNITED KINGDOM | Low end of range [Member]
Operating Loss Carryforwards [Line Items]
Open Tax Year	2010
UNITED KINGDOM | High end of range [Member]
Operating Loss Carryforwards [Line Items]
Open Tax Year	2013