INCOME TAXES Components of Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Deferred Tax Asset
Depreciation	$ 0	$ 0
Deferred compensation	3,210	2,943
Postretirement benefits	8,200	4,364
Net Operating Loss	2,339	0
Allowance for doubtful accounts	260	232
Deferred marketing expenses	0	0
Other assets	183	174
Accrued expenses	2,116	1,241
Tax credits	4,233	3,106
Amortization	0	0
Inventories	256	162
Depletion	0	0
Stock-based compensation	279	426
Reclamation	227	225
Other assets - foreign	40	0
Valuation allowance	(4,061)	(3,106)
Total deferred tax assets	17,282	9,767
Deferred Tax Liability
Depreciation	10,622	5,116
Deferred compensation	0	0
Postretirement benefits	0	0
Net Operating Loss	0	0
Allowance for doubtful accounts	0	0
Deferred marketing expenses	21	442
Other assets	0	0
Accrued expenses	0	0
Tax credits	0	0
Amortization	304	247
Inventories	0	0
Depletion	500	530
Stock-based compensation	0	0
Reclamation	0	0
Other assets - foreign	0	132
Valuation allowance	0	0
Total deferred tax liabilities	$ 11,447	$ 6,467