INCOME TAXES (Details 3) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Deferred tax asset:
Tax loss and tax credit carry-forwards	$ 67,428	$ 45,375
Inventories	25,331	22,476
Compensation and benefits	40,046	39,220
Environmental	4,354	5,616
Accrued expenses	29,514	27,123
Amortization	3,271	4,767
Net pensions	80,901	58,245
Other	31,688	31,393
Gross deferred tax asset	282,533	234,215
Valuation allowance	(20,536)	(22,814)
Total deferred tax asset	261,997	211,401
Deferred tax liability:
Amortization	(46,320)	(12,213)
Plant and equipment	(34,798)	(29,222)
Revenue recognition	(1,754)	(5,692)
Undistributed foreign earnings	(10,799)	(7,270)
Other	(2,817)	(4,096)
Total deferred tax liability	(96,488)	(58,493)
Net deferred tax asset	$ 165,509	$ 152,908