Income Taxes - Schedule of Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Jul. 31, 2018
Tax Credit Carryforward [Line Items]
Deferred Tax Liabilities, Gross	$ 47,270	$ 44,626
Deferred Tax Assets, Gross	36,687	41,693
Deferred Tax Liabilities, Other	7,961	8,962
Deferred Tax Assets, Tax Deferred Expense, Other	7,406	8,548
Deferred Tax Liability, Valuation Allowance	0	0
Deferred Tax Assets, Valuation Allowance	60,073	56,866
Deferred Tax Liabilities Tax Credit Carryforwards And Net Operating Losses	0	0
Deferred Tax Assets, Tax Credit Carryforwards	62,966	64,348
Deferred tax liabilities, deferred tax expense, postretirement benefits	71	0
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits	2,659	3,280
Deferred Tax Liability, Deferred Expense, Deferred Compensation	0	0
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	7,352	10,656
Deferred Tax Liabilities, Intangible Assets	31,415	29,630
Deferred Tax Assets, Goodwill and Intangible Assets	1,432	1,073
Deferred Tax Liabilities, Property, Plant and Equipment	6,869	4,911
Deferred Tax Assets, Property, Plant and Equipment	3,125	2,959
Deferred Tax Liabilities Accounts Receivable	233	1
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts	943	828
Deferred Tax Liabilities Tax Deferred Expense Compensation And Benefits Employee Benefits	89	91
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits	7,021	3,772
Deferred Tax Liabilities, Prepaid Expenses	631	978
Deferred Tax Asset Prepaid Catalog Costs	0	0
Deferred Tax Liabilities, Inventory	1	53
Deferred Tax Assets, Inventory	3,856	3,095
Net of liabilities [Member]
Tax Credit Carryforward [Line Items]
Deferred Tax Assets, Net, Deferred Expense, Compensation and Benefits, Postretirement Benefits		3,280
Deferred Tax Assets, Valuation Allowance	60,073	56,866
Deferred Tax Assets, Tax Credit Carryforwards	62,966	64,348
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits	2,588
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	7,352	10,656
Deferred Tax Liabilities, Intangible Assets		28,557
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts	710	827
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits	6,932	3,681
Deferred Tax Assets, Inventory	3,855	3,042
Net of assets [Member]
Tax Credit Carryforward [Line Items]
Deferred Tax Liabilities, Net	10,583	2,933
Deferred Tax Liabilities, Other	555	414
Deferred Tax Liabilities, Intangible Assets	29,983
Deferred Tax Liabilities, Property, Plant and Equipment	3,744	1,952
Deferred Tax Liabilities, Prepaid Expenses	$ 631	$ 978