Income Taxes - Schedule of Deferred Tax Assets (Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013
Operating Loss Carryforwards [Line Items]
Document Period End Date	Jul. 31, 2014
Deferred Tax Assets, Inventory	$ 5,460	$ 5,880
Deferred Tax Liabilities, Inventory	(126)	(280)
Deferred Tax Asset Prepaid Catalog Costs	30	9
Deferred Tax Liabilities, Prepaid Expenses	(3,180)	(2,407)
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits	1,533	1,973
Deferred Tax Liabilities Tax Deferred Expense Compensation And Benefits Employee Benefits	(27)	(5)
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts	852	1,292
Deferred Tax Liabilities Accounts Receivable	(9)	(63)
Deferred Tax Assets, Other	8,700	9,721
Deferred Tax Liabilities Current Other	(1,015)	(4,684)
Deferred Tax Assets, Gross, Current	16,575	18,875
Deferred Tax Liabilities, Gross, Current	(4,357)	(7,439)
Deferred Tax Assets, Property, Plant and Equipment	2,431	2,717
Deferred Tax Liabilities, Property, Plant and Equipment	(4,587)	(4,811)
Deferred Tax Assets, Goodwill and Intangible Assets	1,706	1,705
Deferred Tax Liabilities, Intangible Assets	(27,381)	(54,008)
Deferred Tax Assets, capitalized R&D	1,425	1,755
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	21,733	24,565
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits	5,002	7,220
Deferred tax liabilities, deferred tax expense, postretirement benefits	(4)
Deferred Tax Assets, Tax Credit Carryforwards	58,870	62,199
Deferred Tax Liabilities Tax Credit Carryforwards And Net Operating Losses	0	(125)
Deferred Tax Assets, Valuation Allowance	(37,409)	(37,142)
Deferred Tax Assets, Tax Deferred Expense, Other	1,411	109
Deferred Tax Liabilities, Other	(6,499)	(8,952)
Deferred Tax Assets, Gross, Noncurrent	55,169	63,128
Deferred Tax Liabilities, Gross, Noncurrent	(38,471)	(67,896)
Deferred Tax Assets, Net	71,744	82,003
Deferred Tax Liabilities, Gross	(42,828)	(75,335)
Net of liabilities [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Inventory	5,334	5,600
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits	1,506	1,968
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts	843	1,229
Deferred Tax Assets, Other	7,685	5,037
Deferred Tax Assets, Gross, Current	12,218	11,436
Deferred Tax Liabilities, Intangible Assets		(52,303)
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits	4,998
Deferred Tax Assets, Tax Credit Carryforwards	58,870	62,074
Deferred Tax Assets, Gross, Noncurrent	16,698
Deferred Tax Liabilities, Gross, Noncurrent		(4,768)
Deferred Tax Assets, Net	28,916	6,668
Net of assets [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Liabilities, Prepaid Expenses	(3,150)	(2,398)
Deferred Tax Liabilities, Property, Plant and Equipment	(2,156)	(2,094)
Deferred Tax Liabilities, Intangible Assets	(25,675)
Deferred Tax Liabilities, Other	$ (5,088)	$ (8,843)