Basis of Presentation and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Apr. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements have been prepared in accordance with the U.S. Securities and Exchange Commission (“SEC”) instructions to Quarterly Reports on Form 10-Q and include all of the information and disclosures required by accounting principles generally accepted in the United States (“GAAP”) for interim financial reporting. The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual amounts could differ from those estimates. The Company’s fiscal year begins on November 1 and ends on October 31 of the following year. Any references to the year 2017 or 2016, or to any quarter of those years, relates to the fiscal year or quarter, as the case may be, ended in that year. The information filed herein reflects all adjustments that are, in the opinion of management, necessary for a fair presentation of the condensed consolidated balance sheets as of April 30, 2017 and October 31, 2016, the condensed consolidated statements of income and comprehensive income for the three and six months ended April 30, 2017 and 2016 and the condensed consolidated statements of cash flows for the six months ended April 30, 2017 and 2016 of Greif, Inc. and its subsidiaries (the “Company”). The condensed consolidated financial statements include the accounts of Greif, Inc., all wholly-owned and consolidated subsidiaries and investments in limited liability companies, partnerships and joint ventures in which it has controlling influence or is the primary beneficiary. Non-majority owned entities include investments in limited liability companies, partnerships and joint ventures in which the Company does not have controlling influence and are accounted for using either the equity or cost method, as appropriate. The unaudited condensed consolidated financial statements included in the Quarterly Report on Form 10-Q (this “Form 10-Q”) should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for its fiscal year ended October 31, 2016 (the “2016 Form 10-K”).
Newly Adopted Accounting Standards and Recently Issued Accounting Standards	Newly Adopted Accounting Standards In February 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2015-02, “Consolidation (Topic 810): Amendments to the Consolidation Analysis,” which makes changes to both the variable interest model and the voting interest model and eliminates the indefinite deferral of FASB Statement No. 167, included in ASU 2010-10, for certain investment funds. All reporting entities that hold a variable interest in other legal entities were required to re-evaluate their consolidation conclusions as well as disclosure requirements. The Company adopted the new guidance beginning on November 1, 2016, and the adoption did not have a material impact on the Company's financial position, results of operations, comprehensive income, cash flows or disclosures. In January 2017, the FASB issued ASU 2017-04, “Intangibles - Goodwill and Other (Topic 350),” which simplifies the subsequent measurement of goodwill in Accounting Standards Codification ("ASC") 350 by eliminating the step 2 requirement to perform procedures to determine the fair value at the impairment testing date of assets and liabilities in order to calculate goodwill impairment based on the implied fair value of goodwill. This amendment modifies the concept of impairment from the condition that exists when the carrying amount of goodwill exceeds its implied fair value to the condition that exists when the carrying amount of a reporting unit exceeds its fair value. The Company elected to adopt the new guidance beginning on February 1, 2017 using a prospective approach, and the adoption did not have a material impact on the Company's financial position, results of operations, comprehensive income, cash flows or disclosures. Recently Issued Accounting Standards The FASB has issued ASUs through 2017-10. The Company has reviewed each recently issued ASU. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” which supersedes the revenue recognition requirements in ASC 605, Revenue Recognition. This ASU is based on the principle that revenue is recognized to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. The update is effective on November 1, 2018 using one of two retrospective application methods. The Company is in the process of determining the potential impact of adopting the new revenue standards, but anticipates that the impact of adoption will be limited to expanded disclosures with no material impact on its financial position, results of operations, comprehensive income, or cash flow. In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)," which amends the lease accounting and disclosure requirements in ASC 842, "Leases". The objective of this update is to increase transparency and comparability among organizations recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about lease arrangements. This ASU will require the recognition of lease assets and lease liabilities for those leases classified as operating leases under previous GAAP. The update is effective on November 1, 2019 using a modified retrospective approach. The Company is in the process of determining the potential impact of adopting this guidance on its financial position, results of operations, comprehensive income, cash flows and disclosures. In October 2016, the FASB issued ASU 2016-16, "Intra-Equity Transfers of Assets Other Than Inventory (Topic 740)," which improves the accounting for income tax consequences of intra-entity transfers of assets other than inventory. This ASU is effective on November 1, 2018 and early adoption is permitted, including any interim period. The Company is in the process of determining the potential impact of adopting this guidance on its financial position, results of operations, comprehensive income, cash flows and disclosures. In March 2017, the FASB issued ASU 2017-07, "Compensation - Retirement Benefits (Topic 715)," which provides additional guidance in ASC 715 for the presentation of net periodic benefit cost in the income statement and on the components eligible for capitalization in assets. This ASU will require the reporting of the service cost component to be in the same line item as other compensation costs arising from services rendered by the pertinent employees. Also, the other components of net benefit cost will be required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations. This update also allows only the service cost component to be eligible for capitalization when applicable. The update is effective on November 1, 2018 using a retrospective approach for the presentation of the service cost component and the other components of net periodic pension cost and net periodic post-retirement benefit cost in the income statement and prospectively, on and after the effective date, for the capitalization of the service cost component of net periodic pension cost and net periodic post-retirement benefit in assets. The Company is in the process of determining the potential impact of adopting this guidance on its financial position, results of operations, comprehensive income, cash flows and disclosures.
Income Taxes	Income tax expense for the quarter was computed in accordance with ASC 740-270 "Income Taxes - Interim Reporting" (ASC 740-270). Under this method, losses from jurisdictions for which a valuation allowance has been provided have not been included in the amount to which the ASC 740-270 rate was applied. Income tax expense of the Company fluctuates primarily due to changes in income mix by jurisdiction, including changes in losses and income from jurisdictions for which a valuation allowance has been provided, and the impact of discrete items in the respective quarter.

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.