Income Taxes - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Jan. 31, 2012	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Income Taxes [Line Items]
Income tax refund received	$ 12,007
Income Tax expense benefit		1,128	4,312	5,668
Professional fees related to refund of Tax		2,714
Unrecognized tax benefits		(6,756)	(16,250)	(12,124)
Unrecognized tax benefits that would impact effective tax rate		6,756
Unrecognized tax benefits, interest on income taxes expense		900
Reduction in uncertain tax benefits and accrued interest		11,389
Unrecognized tax benefits, accrued interest and penalties		640	1,485
Deferred tax assets		8,810	8,389
Refundable income tax assets		976	1,288
BELGIUM
Income Taxes [Line Items]
Net operating loss carryforwards, not subject to expiration		3,659
ITALY
Income Taxes [Line Items]
Net operating loss carryforwards, subject to expiration		378
Net operating loss carryforwards, expiration year		2017
CHINA
Income Taxes [Line Items]
Net operating loss carryforwards, subject to expiration		781
Net operating loss carryforwards, expiration year		2015
Valuation allowance amount		148
State and Local Jurisdiction
Income Taxes [Line Items]
State tax credit carryforwards		8,519
State tax credit carryforwards, expiration year		2026
Income Tax Refund
Income Taxes [Line Items]
Income Tax expense benefit		(10,025)
Reversal and Re-Measurement of Tax Reserves
Income Taxes [Line Items]
Income Tax expense benefit		(2,308)
Reversal Of Tax Reserves | State non-U.S. Taxes
Income Taxes [Line Items]
Income Tax expense benefit		$ 358