Business to Business Products Business to Business Segment [Member] Business to Business Segment [Member] Granted, number of shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Document Type Document Type Other, net Other Nonoperating Income (Expense) Related Party [Axis] Related Party [Axis] Payables and Accruals [Abstract] Other intangibles, net of accumulated amortization of $540 and $457 at April 30, 2021 and July 31, 2020, respectively Trademarks and patents, net The total amount, net of amortization, as of the balance sheet date for 1) the rights acquired through registration of a trademark to gain or protect exclusive use of a business name, symbol or other device or style for a projected indefinite period of benefit and 2) costs pertaining to the exclusive legal rights granted to the owner of the patent to exploit an invention or a process for a period of time specified by law. 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Accumulated Other Comprehensive Loss: Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Settlement loss due to annuity purchase Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement Estimated contributions in remainder of current fiscal year Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Inventory [Axis] Inventory [Axis] Statement Statement [Line Items] Condensed Consolidated Statements of Comprehensive Income [Abstract] Condensed Consolidated Statements of Comprehensive Income [Abstract] Condensed Consolidated Statements of Comprehensive Income [Abstract] Class of Stock [Domain] Class of Stock [Domain] Statement [Table] Statement [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Interest cost Defined Benefit Plan, Interest Cost Payments In Advance Up-front Payment Arrangement [Member] Lessee, Operating Lease, Liability, Payment, Due, Rolling Maturity Lessee, Operating Lease, Liability, Payment, Due, Rolling Maturity [Abstract] Entity Small Business Entity Small Business Revenue Recognition [Abstract] Revenue Recognition [Abstract] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Customer list, net of accumulated amortization of $7,212 and $6,887 at April 30, 2021 and July 31, 2020, respectively Customer list, net Gross carrying amount before accumulated amortization as of the balance sheet date of an asset comprised of customer information, acquired in a business combination or other transaction, having a finite beneficial life. Fair Value Measurement [Domain] Fair Value Hierarchy and NAV [Domain] Amendment Flag Amendment Flag Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Number Authorized (shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Number Available (shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Fair Value Measurement, Policy Fair Value Measurement, Policy [Policy Text Block] Net Cash Provided by Operating Activities Net Cash Provided by (Used in) Operating Activities Entity Central Index Key Entity Central Index Key Related Party [Domain] Related Party [Domain] Defined Benefit Plans and Other Postretirement Benefit Plans Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Related Party Transaction Related Party Transaction [Line Items] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Cash Equivalents Cash Equivalents, at Carrying Value Capital expenditures accrued, but not paid Capital Expenditures Incurred but Not yet Paid Subsequent Events [Text Block] Subsequent Events [Text Block] Segment [Domain] Segments [Domain] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Schedule of Restricted Stock Transactions Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] Effect of exchange rate changes on Cash and Cash Equivalents Effect of Exchange Rate on Cash and Cash Equivalents Allowance for doubtful accounts Accounts Receivable, Allowance for Credit Loss, Current Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding CASH FLOWS FROM FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities [Abstract] Trade promotions and advertising Accrued Marketing Costs, Current Selling, General and Administrative Expenses Selling, General and Administrative Expense Amortization of intangible assets Amortization of Intangible Assets Lease cost Lease, Cost [Table Text Block] Other Other Assets, Noncurrent Plan Name [Axis] Plan Name [Axis] Deferred Revenue Arrangement Type [Axis] Deferred Revenue Arrangement Type [Axis] Operating Segment Disclosure Segment Reporting Disclosure [Text Block] Accounts receivable, less allowance of   $993 and $1,078 at April 30, 2021 and July 31, 2020, respectively Receivables, Net, Current Total Assets Assets Assets Related Party Transactions Disclosure Related Party Transactions Disclosure [Text Block] Statement, Scenario [Axis] Scenario [Axis] Interest expense Interest Expense, Debt Non-vested restricted stock outstanding, beginning balance Non-vested restricted stock outstanding, ending balance Share-based Compensation Arrangement by Share-based Payment Award, 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[Abstract] Fair Value, Inputs, Level 1 Fair Value, Inputs, Level 1 [Member] Inventories Increase (Decrease) in Inventories Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Additional Paid-in Capital Additional Paid-in Capital [Member] Revenue by Principal Product Disaggregation of Revenue [Line Items] Accrued expenses Increase (Decrease) in Accrued Liabilities Purchases of treasury stock Treasury Stock, Value, Acquired, Cost Method Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Common & Class B Stock, Beginning of Period (in shares) Common Stock & Class B Stock, End of Period (in shares) Common Stock, Shares, Outstanding Entity Information Entity Information [Line Items] Deferred compensation Increase (Decrease) in Deferred Compensation Average Shares Outstanding Weighted Average Shares Outstanding [Abstract] Weighted Average Shares Outstanding [Abstract] Income Before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Subsequent Event Subsequent Event [Member] Cost Property, Plant and Equipment, Gross Revenue Recognition Revenue [Policy Text Block] Operating Segments Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Noncontrolling Interest, Parent Ownership Percentage Prior to Purchase of Additional Interest Noncontrolling Interest, Parent Ownership Percentage Prior to Purchase of Additional Interest The parent entity's interest in net assets of the subsidiary, expressed as a percentage prior to the purchase of additional interest Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Principal payments on notes payable Repayments of Senior Debt Long-term operating lease liabilities Operating Lease, Liability, Noncurrent 2025 Finite-Lived Intangible Asset, Expected Amortization, Year Four Prepaid expenses Increase (Decrease) in Prepaid Expense and Other Assets Pension and postretirement benefits (net of tax) Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Current Assets Assets, Current [Abstract] Interest income Investment Income, Interest Schedule of Assumptions Used Defined Benefit Plan, Assumptions [Table Text Block] Total Comprehensive Income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Scenario [Domain] Scenario [Domain] Capital expenditures Payments to Acquire Property, Plant, and Equipment City Area Code City Area Code Document Period End Date Document Period End Date Goodwill and Other Intangible Assets Goodwill and 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adjustment from AOCI for pension and other postretirement benefits Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax Revenue by Principal Product by Operating Segment [Table] Disaggregation of Revenue [Table] 2025 Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Five Inventories Schedule of Inventory, Current [Table Text Block] Stock-based compensation Share-based Payment Arrangement, Noncash Expense Payments in Advance, Revenue Recognized Deferred Revenue, Revenue Recognized Cover [Abstract] Cover [Abstract] Other comprehensive income before reclassifications, net of tax Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Property, Plant and Equipment Property, Plant and Equipment, Net [Abstract] Overburden Removal and Mining Costs Overburden Removal and Mining Costs [Policy Text Block] Description of accounting policy for overburden removal/stripping costs for mined properties and other 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Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract] Lessee, Operating Leases Lessee, Operating Leases [Text Block] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Service cost Defined Benefit Plan, Service Cost 2006 Plan 2006 Plan [Member] 2006 Plan [Member] Cost of Sales Cost of Goods and Services Sold Lease, Cost Lease, Cost [Abstract] Equity Components [Axis] Equity Components [Axis] Restricted Stock Restricted Stock [Member] Reclamation Asset Retirement Obligation [Policy Text Block] Share-based Payment Arrangement [Abstract] Share-based Payment Arrangement [Abstract] Operating lease liabilities Operating Lease, Liability, Current Ultimate Health Care Cost Trend Rate Defined Benefit Plan, Ultimate Health Care Cost Trend Rate Net (Loss) Income Attributable to Noncontrolling Interest Net Income (Loss) Attributable to Noncontrolling Interest 2022 Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Two Forfeitures, weighted average grant date fair value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Amortization of Other actuarial loss Defined Benefit Plan, Amortization of Gain (Loss) Entity Interactive Data Current Entity Interactive Data Current Net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Fair Value Measurements Fair Value Disclosures [Text Block] CASH FLOWS FROM OPERATING ACTIVITIES Net Cash Provided by (Used in) Operating Activities [Abstract] Segment Income Segment Reporting Information, Operating Income for Reportable Segment Segment Reporting Information, Operating Income for Reportable Segment Amortization expense for remainder of current fiscal year Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year Additional paid-in capital Additional Paid in Capital, Common Stock Depreciation and amortization Depreciation, Amortization and Accretion, Net Entity Registrant Name Entity Registrant Name Subsequent Event Type [Domain] Subsequent Event Type [Domain] Cumulative translation adjustment Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Weighted-average discount rate - operating leases Operating Lease, Weighted Average Discount Rate, Percent Other liabilities Increase (Decrease) in Other Operating Liabilities Total Other Assets Assets, Noncurrent Noncontrolling Interest Noncontrolling Interest Agromex [Member] Noncontrolling Interest Agromex [Member] Proceeds from sale of property, plant, and equipment Proceeds from Sale of Property, Plant, and Equipment Number of Reportable Segments Number of Reportable Segments Retirement Plan Type [Domain] Retirement Plan Type [Domain] Accumulated amortization of customer lists Customer list accumulated amortization Accumulated amortization as of the balance sheet date that pertains to a customer list finite-lived intangible asset. Dividends paid Payments of Ordinary Dividends, Common Stock Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Goodwill impairment loss Goodwill, Impairment Loss Finished goods Inventory, Finished Goods, Gross Pension and postretirement benefits Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax Total Lessee, Operating Lease, Liability, to be Paid Noncontrolling Interest, Ownership Percentage by Parent Noncontrolling Interest, Ownership Percentage by Parent Bleaching Clay and Fluids Purification Bleaching Clay and Fluids Purification [Member] Information about principal product: Bleaching Clay and Fluids Purification [Member] Adjustments for New Accounting Pronouncements [Axis] Accounting Standards Update [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Prepaid expenses and other assets Other Prepaid Expense, Current Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] Goodwill Goodwill Corporate Expenses Corporate Expenses The corporate expenses line represents certain unallocated expenses, including primarily salaries, wages and benefits, purchased services, rent, utilities and depreciation and amortization associated with corporate functions such as research and development, information systems, finance, legal, human resources and customer service. Corporate expenses also include the annual incentive plan bonus accrual. Document Transition Report Document Transition Report Other Income (Expense) Nonoperating Income (Expense) [Abstract] Dividends Declared Per Share (in dollars per share) Common Stock, Dividends, Per Share, Declared Fair Value, Inputs, Level 2 Fair Value, Inputs, Level 2 [Member] Document Quarterly Report Document Quarterly Report Supplemental disclosure of non-cash investing and financing activities: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Subsequent Event Subsequent Event [Line Items] Entities [Table] Entities [Table] Noncontrolling Interest, Ownership Percentage Prior to Parent's Purchase of Additional Interest Noncontrolling Interest Ownership Percentage Prior to Parent's Purchase of Additional Interest The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity. prior to purchase of additional interest by Parent New Accounting Pronouncements Accounting Standards Update and Change in Accounting Principle [Text Block] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Diluted Common (in shares) Weighted Average Number of Shares Outstanding, Diluted Basic Common (in dollars per share) Earnings Per Share, Basic NEW ACCOUNTING PRONOUNCEMENTS [Abstract] NEW ACCOUNTING PRONOUNCEMENTS [Abstract] NEW ACCOUNTING PRONOUNCEMENTS [Abstract] Entity File Number Entity File Number Schedule of Accounts Payable and Accrued Liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Forfeitures, number of shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Real Estate Tax Accrual for Taxes Other than Income Taxes, Current Curtailment gain on SERP Plan Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment Pension and postretirement benefits Liability, Defined Benefit Plan, Noncurrent Rate of increase in compensation levels Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase Weighted-average remaining lease term - operating leaes Operating Lease, Weighted Average Remaining Lease Term Inventory, Current [Table] Inventory, Current [Table] Voluntary contributions Defined Benefit Plan Voluntary Contribution Defined Benefit Plan Voluntary Contribution Net Cash Used in Financing Activities Net Cash Provided by (Used in) Financing Activities Contributions from noncontrolling interests Proceeds from Noncontrolling Interests 2021 Lessee, Operating Lease, Liability, Payments, Due Next Rolling Twelve Months Deferred Revenue Deferred Revenue [Domain] Inventory obsolescence reserve Inventory Valuation Reserves Share-based Compensation Expense Share-based Payment Arrangement, Expense Common Stock, Value, Issued Common Stock, Value, Issued Industrial and Sports Industrial and Sports [Member] Information about principal product: Industrial and Sports [Member] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Finite-Lived Intangible Assets, Future Amortization Expense Finite-Lived Intangible Assets Finite-Lived Intangible Assets [Line Items] Document Fiscal Year Focus Document Fiscal Year Focus 2023 Finite-Lived Intangible Asset, Expected Amortization, Year Two Entity Current Reporting Status Entity Current Reporting Status Subsequent Event [Table] Subsequent Event [Table] Net issuance of stock under long-term incentive plans (in shares) Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture Noncontrolling interest Stockholders' Equity Attributable to Noncontrolling Interest Granted, weighted average grant date fair value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Inventory Disclosure [Abstract] Inventory Disclosure [Abstract] CASH FLOWS FROM INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities [Abstract] Common stock, shares issued Common Stock, Shares, Issued Cash and cash equivalents Cash and Cash Equivalents, Beginning of Period Cash and Cash Equivalents, End of Period Cash and Cash Equivalents, at Carrying Value CARES Act, Current Payroll Tax Deferral CARES Act, Current Payroll Tax Deferral On March 27, 2020, in response to the COVID-19 pandemic, the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) was signed into U.S. law. The CARES Act provides for, among other things, deferral of the employer portion of social security taxes incurred through the end of calendar 2020. Parent Parent Oil-Dri Corporation of America [Member] Parent Oil-Dri Corporation of America [Member] Agricultural and Horticultural Agricultural and Horticultural [Member] Information about principal product: Agricultural and Horticultural [Member] Net lease obligation Operating Lease, Liability Segment Reporting [Abstract] Segment Reporting [Abstract] Basis of Statement Presentation Basis of Presentation and Significant Accounting Policies [Text Block] Cat Litter Cat Litter [Member] Information about principal product: Cat Litter [Member] Total Liabilities & Stockholders’ Equity Liabilities and Equity Total Accumulated Other Comprehensive Loss Accumulated Other Comprehensive (Loss) Income, Balance, beginning Accumulated Other Comprehensive (Loss) Income, Balance, ending Accumulated Other Comprehensive Income (Loss), Net of Tax Total Noncurrent Liabilities Liabilities, Noncurrent Entity Address, City or Town Entity Address, City or Town Salaries, Wages, Commissions and Employee Benefits Employee-related Liabilities, Current Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Medical Cost Trend Assumption Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year Other Assets Other Assets, Noncurrent [Abstract] Operating lease cost Operating Lease, Cost Type of Adoption [Domain] Accounting Standards Update [Domain] Deferred Revenue Arrangement Deferred Revenue Arrangement [Line Items] Short-term operating lease cost Short-term Lease, Cost Loss on the sale of fixed assets Gain (Loss) on Disposition of Property Plant Equipment Total Stockholders' Equity Total Accumulated Other Comprehensive (Loss) Income Equity Component [Domain] Gross Profit Gross Profit Total Property, Plant and Equipment, Net Property, Plant and Equipment, Net 2024 Finite-Lived Intangible Asset, Expected Amortization, Year Three Increase (Decrease) in liabilities: Increase (Decrease) in Operating Liabilities [Abstract] Entity Tax Identification Number Entity Tax Identification Number Deferred compensation Deferred Compensation Liability, Classified, Noncurrent Disclosure of Compensation Related Costs, Share-based Payments Share-based Payment Arrangement [Text Block] Net Income Attributable to Oil-Dri Net Income Attributable to Oil-Dri Net Income (Loss) Attributable to Parent (Increase) Decrease in assets: Increase (Decrease) in Operating Assets [Abstract] Inventories Inventory Disclosure [Text Block] Other Comprehensive Income Other comprehensive income Net current-period other comprehensive income, net of tax Other Comprehensive Income (Loss), Net of Tax Leases [Abstract] Leases [Abstract] Accounts payable to related party Accounts Payable, Related Parties, Current Amount Contributed to Purchase of Additional Interest by Parent Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Purchase of Interest by Parent Total Current Assets Assets, Current Current Fiscal Year End Date Current Fiscal Year End Date Net Income Per Share Earnings Per Share [Abstract] Pension and Postretirement Health Benefits Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Accumulated Other Comprehensive (Loss) Income Accumulated Other Comprehensive Income (Loss) [Line Items] 2026 Finite-Lived Intangible Asset, Expected Amortization, Year Five Document Fiscal Period Focus Document Fiscal Period Focus Treasury Stock Treasury Stock, Common [Member] Consolidated Statements of Stockholders' Equity [Abstract] Consolidated Statements of Stockholders' Equity [Abstract] Consolidated Statements of Stockholders' Equity [Abstract] Award Vesting Period, Maximum (years) ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPeriodMaximum Maximum period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition Entity Filer Category Entity Filer Category Common Stock Common & Class B Stock Common Stock [Member] Cumulative Translation Adjustment Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Prinicipal Products [Domain] Product and Service [Domain] Current maturities of notes payable Senior Notes, Current Inventory [Domain] Inventory [Domain] Contributions from noncontrolling interests Proceeds from (Payments to) Noncontrolling Interests Condensed Consolidated Statements of Income and Retained Earnings [Abstract] Condensed Consolidated Statements of Income and Retained Earnings [Abstract] Condensed Consolidated Statements of Income and Retained Earnings [Abstract] Other Other Inventory, Gross Dividends payable Dividends Payable, Current 2024 Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Four Provision for bad debts and cash discounts Accounts Receivable, Credit Loss Expense (Reversal) Less accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Related Party Transactions [Abstract] Related Party Transactions [Abstract] Net Decrease in Cash and Cash Equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Total Other Income (Expense), Net Total Other Income (Expense), Net Nonoperating Income (Expense) Accumulated amortization of other intangibles TrademarksAndPatentsAccumulated Amortization The accumulated amount of amortization of the costs pertaining to the rights acquired through registration of a trademark to gain or protect exclusive use of a business name, symbol or other device or style for a projected indefinite period of benefit PLUS the accumulated amount of amortization of the costs pertaining to the exclusive legal rights granted to the owner of the patent to exploit an invention or a process for a period of time specified by law. Notes payable, net of unamortized debt issuance costs of $129 and $150 at April 30, 2021 and July 31, 2020, respectively Senior Notes, Noncurrent Operating lease payments due within next twelve months as of April 30, 2021 Lessee, Operating Lease, Liability, Maturity [Table Text Block] Noncontrolling Interest Items [Abstract] Noncontrolling Interest Items [Abstract] Basic Common (in shares) Weighted Average Number of Shares Outstanding, Basic Subsequent Events [Abstract] Subsequent Events [Abstract] Ownership [Axis] Ownership [Axis] Cumulative translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Treasury stock, common shares Treasury Stock, Shares Treasury Stock, Beginning of Period (in shares) Treasury Stock, End of Period (in shares) Treasury Stock, Common, Shares Ownership Ownership [Domain] Plan Name [Domain] Plan Name [Domain] Long-term expected rate of return on assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets Cash dividends declared and accrued, but not paid Dividends Payable Packaging Packaging Inventory Packaging Inventory Total Stockholders' Equity Total, Beginning of Period Total, End of Period Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest 2022 Finite-Lived Intangible Asset, Expected Amortization, Year One Notes Payable, Fair Value Long-term Debt, Fair Value Class of Stock [Axis] Class of Stock [Axis] Inventories Inventory, Policy [Policy Text Block] Income Tax Benefit (Expense) Income Tax Expense (Benefit) Year that Rate Reaches Ultimate Trend Rate Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate New Accounting Pronouncements or Change in Accounting Principle [Table] Accounting Standards Update and Change in Accounting Principle [Table] Accrued expenses Accrued Liabilities, Current Diluted Common (in dollars per share) Earnings Per Share, Diluted Local Phone Number Local Phone Number Noncontrolling Interest Noncontrolling Interest [Line Items] Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Other assets Increase (Decrease) in Other Operating Assets Entity Emerging Growth Company Entity Emerging Growth Company Indefinite-lived trademarks Indefinite-lived Intangible Assets (Excluding Goodwill) Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Deferred income taxes Deferred Income Tax Expense (Benefit) Selling, General and Administrative Expenses Selling, General and Administrative Expenses, Policy [Policy Text Block] Award Type [Axis] Award Type [Axis] Discount rate for net periodic benefit cost Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Noncontrolling Interest Noncontrolling Interest [Member] Dividends declared Dividends, Common Stock, Cash Retained Earnings Retained Earnings [Member] Condensed Consolidated Balance Sheet Parenthetical [Abstract] Condensed Consolidated Balance Sheet Parenthetical [Abstract] Condensed Consolidated Balance Sheet Parenthetical [Abstract] Schedule of Net Benefit Costs Schedule of Net Benefit Costs [Table Text Block] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Net Cash Used in Investing Activities Net Cash Provided by (Used in) Investing Activities Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Freight Accrued Freight Accrued Freight Award Type [Domain] Award Type [Domain] Noncurrent Liabilities Liabilities, Noncurrent [Abstract] Other Accounts Payable and Other Accrued Liabilities, Current Postretirement Health Plan Postretirement Health Plan Other Postretirement Benefits Plan [Member] Trading Symbol Trading Symbol Net sales to related party Revenue from Related Parties Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Less Treasury Stock, at cost (3,186,801 Common and 346,491 Class B shares at April 30, 2021 and 3,090,230 Common and 335,816 Class B shares at July 31, 2020) Treasury Stock, Value Pension Plan Pension Plan [Member] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Current Liabilities Liabilities, Current [Abstract] Entity Shell Company Entity Shell Company Segment Reporting Information Segment Reporting Information [Line Items] Operating Segments Segment Reporting, Policy [Policy Text Block] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract]