Income Taxes - Schedule of Deferred Tax Assets (Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2013	Jul. 31, 2012
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Inventory	$ 5,880	$ 4,984
Deferred Tax Liabilities, Inventory	(280)	(4)
Deferred Tax Asset Prepaid Catalog Costs	9	13
Deferred Tax Liabilities, Prepaid Expenses	(2,407)	(3,520)
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits	1,973	2,980
Deferred Tax Liabilities Tax Deferred Expense Compensation And Benefits Employee Benefits	(5)	(4)
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts	1,292	1,370
Deferred Tax Liabilities Accounts Receivable	(63)	(11)
Deferred Tax Assets, Other	9,721	7,267
Deferred Tax Liabilities Current Other	(4,684)	(3,221)
Deferred Tax Assets, Gross, Current	18,875	16,614
Deferred Tax Liabilities, Gross, Current	(7,439)	(6,760)
Deferred Tax Assets, Property, Plant and Equipment	2,717	2,146
Deferred Tax Liabilities, Property, Plant and Equipment	(4,811)	(5,703)
Deferred Tax Assets, Goodwill and Intangible Assets	1,705	1,885
Deferred Tax Liabilities, Intangible Assets	(54,008)	(39,561)
Deferred Tax Assets, capitalized R&D	1,755	2,047
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	24,565	27,122
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits	7,220	7,429
Deferred Tax Assets, Tax Credit Carryforwards	62,199	68,148
Deferred Tax Liabilities Tax Credit Carryforwards And Net Operating Losses	(125)	0
Deferred Tax Assets, Valuation Allowance	(37,142)	(25,847)
Deferred Tax Assets, Tax Deferred Expense, Other	109	156
Deferred Tax Liabilities, Other	(8,952)	(7,146)
Deferred Tax Assets, Gross, Noncurrent	63,128	83,086
Deferred Tax Liabilities, Gross, Noncurrent	(67,896)	(52,410)
Deferred Tax Assets, Net	82,003	99,700
Deferred Tax Liabilities, Gross	(75,335)	(59,170)
Net of liabilities [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Inventory	5,600	4,980
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits	1,968	2,976
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts	1,229	1,359
Deferred Tax Assets, Other	5,037	4,046
Deferred Tax Assets, Gross, Current	11,436	9,854
Deferred Tax Liabilities, Intangible Assets	(52,303)	(37,676)
Deferred Tax Assets, Tax Credit Carryforwards	62,074	68,148
Deferred Tax Liabilities, Gross, Noncurrent	(4,768)	30,676
Deferred Tax Assets, Net	6,668	40,530
Net of assets [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Liabilities, Prepaid Expenses	(2,398)	(3,507)
Deferred Tax Liabilities, Property, Plant and Equipment	(2,094)	(3,557)
Deferred Tax Liabilities, Other	$ (8,843)	$ (6,990)