Basis of Presentation	3 Months Ended
Aug. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	NOTE A – Basis of Presentation The consolidated financial statements include the accounts of Worthington Industries, Inc. and consolidated subsidiaries (collectively, “we,” “our,” “Worthington,” or the “Company”). Investments in unconsolidated affiliates are accounted for using the equity method. Significant intercompany accounts and transactions are eliminated. The Company owns controlling interests in the following three joint ventures: Spartan Steel Coating, LLC (“Spartan”) (52%), TWB Company, L.L.C. (“TWB”) (55%), and Worthington Specialty Processing (“WSP”) (51%). These joint ventures are consolidated with the equity owned by the other joint venture members shown as noncontrolling interests in our consolidated balance sheets, and their portions of net earnings and other comprehensive income (“OCI”) shown as net earnings or comprehensive income attributable to noncontrolling interests in our consolidated statements of earnings and consolidated statements of comprehensive income, respectively. These unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the United States Securities and Exchange Commission (“SEC”). Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments, which are of a normal and recurring nature except those which have been disclosed elsewhere in this Quarterly Report on Form 10-Q, necessary for a fair presentation of the consolidated financial statements for these interim periods, have been included. Operating results for the three months ended August 31, 2018 are not necessarily indicative of the results that may be expected for the fiscal year ending May 31, 2019 (“fiscal 2019”). For further information, refer to the consolidated financial statements and notes thereto included in the Annual Report on Form 10-K for the fiscal year ended May 31, 2018 (“fiscal 2018”) of Worthington Industries, Inc. (the “2018 Form 10-K”). The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Recently Adopted Accounting Standards On June 1, 2018, the Company adopted new accounting guidance that replaces most existing revenue recognition guidance under U.S. GAAP. See “NOTE B – Revenue Recognition” for further explanation related to this adoption, including newly required disclosures. Recently Issued Accounting Standards In February 2016, new accounting guidance was issued that replaces most existing lease accounting guidance under U.S. GAAP. Among other changes, the new guidance requires that leased assets and liabilities be recognized on the balance sheet by lessees for those leases classified as operating leases under previous guidance. The new guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted, and the change is to be applied using a modified retrospective approach as of the beginning of the earliest period presented. In July 2018, the FASB issued additional accounting standard updates clarifying certain provisions, as well as providing for a second transition method allowing entities to initially apply the standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance sheet of retained earnings. We are in the process of evaluating the effect this guidance will have on our consolidated financial position, results of operations and cash flows, and we have not determined the effect of the new guidance on our ongoing financial reporting. In June 2016, amended accounting guidance was issued related to the measurement of credit losses on financial instruments. The amended guidance changes the impairment model for most financial assets to require measurement and recognition of expected credit losses for financial assets held. The amended guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. We are in the process of evaluating the effect this guidance will have on our consolidated financial position and results of operations; however, we do not expect the new guidance to have a material impact on our ongoing financial reporting. In August 2017, amended accounting guidance was issued that modifies hedge accounting by making more hedge strategies eligible for hedge accounting, amending presentation and disclosure requirements, and changing how companies assess effectiveness. The intent is to simplify application of hedge accounting and increase transparency of information about an entity’s risk management activities. The amended guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. It is to be applied using a modified retrospective transition approach for cash flow and net investment hedges existing at the date of adoption. The presentation and disclosure guidance is only required prospectively. Early adoption is permitted. We are in the process of evaluating the effect this guidance will have on our consolidated financial position and results of operations, and have not determined the effect on our ongoing financial reporting.

NOTE A – Basis of Presentation

The consolidated financial statements include the accounts of Worthington Industries, Inc. and consolidated subsidiaries (collectively, “we,” “our,” “Worthington,” or the “Company”). Investments in unconsolidated affiliates are accounted for using the equity method. Significant intercompany accounts and transactions are eliminated.

The Company owns controlling interests in the following three joint ventures: Spartan Steel Coating, LLC (“Spartan”) (52%), TWB Company, L.L.C. (“TWB”) (55%), and Worthington Specialty Processing (“WSP”) (51%). These joint ventures are consolidated with the equity owned by the other joint venture members shown as noncontrolling interests in our consolidated balance sheets, and their portions of net earnings and other comprehensive income (“OCI”) shown as net earnings or comprehensive income attributable to noncontrolling interests in our consolidated statements of earnings and consolidated statements of comprehensive income, respectively.

These unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the United States Securities and Exchange Commission (“SEC”). Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments, which are of a normal and recurring nature except those which have been disclosed elsewhere in this Quarterly Report on Form 10-Q, necessary for a fair presentation of the consolidated financial statements for these interim periods, have been included. Operating results for the three months ended August 31, 2018 are not necessarily indicative of the results that may be expected for the fiscal year ending May 31, 2019 (“fiscal 2019”). For further information, refer to the consolidated financial statements and notes thereto included in the Annual Report on Form 10-K for the fiscal year ended May 31, 2018 (“fiscal 2018”) of Worthington Industries, Inc. (the “2018 Form 10-K”).

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates.

Recently Adopted Accounting Standards

On June 1, 2018, the Company adopted new accounting guidance that replaces most existing revenue recognition guidance under U.S. GAAP. See “NOTE B – Revenue Recognition” for further explanation related to this adoption, including newly required disclosures.

Recently Issued Accounting Standards

In February 2016, new accounting guidance was issued that replaces most existing lease accounting guidance under U.S. GAAP. Among other changes, the new guidance requires that leased assets and liabilities be recognized on the balance sheet by lessees for those leases classified as operating leases under previous guidance. The new guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted, and the change is to be applied using a modified retrospective approach as of the beginning of the earliest period presented. In July 2018, the FASB issued additional accounting standard updates clarifying certain provisions, as well as providing for a second transition method allowing entities to initially apply the standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance sheet of retained earnings. We are in the process of evaluating the effect this guidance will have on our consolidated financial position, results of operations and cash flows, and we have not determined the effect of the new guidance on our ongoing financial reporting.

In June 2016, amended accounting guidance was issued related to the measurement of credit losses on financial instruments. The amended guidance changes the impairment model for most financial assets to require measurement and recognition of expected credit losses for financial assets held. The amended guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. We are in the process of evaluating the effect this guidance will have on our consolidated financial position and results of operations; however, we do not expect the new guidance to have a material impact on our ongoing financial reporting.

In August 2017, amended accounting guidance was issued that modifies hedge accounting by making more hedge strategies eligible for hedge accounting, amending presentation and disclosure requirements, and changing how companies assess effectiveness. The intent is to simplify application of hedge accounting and increase transparency of information about an entity’s risk management activities. The amended guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. It is to be applied using a modified retrospective transition approach for cash flow and net investment hedges existing at the date of adoption. The presentation and disclosure guidance is only required prospectively. Early adoption is permitted. We are in the process of evaluating the effect this guidance will have on our consolidated financial position and results of operations, and have not determined the effect on our ongoing financial reporting.