Equity	12 Months Ended
May 31, 2018
Equity [Abstract]
Equity	Note I – Equity Preferred Shares: The Worthington Industries, Inc. Amended Articles of Incorporation authorize two classes of preferred shares and their relative voting rights. The Board of Directors of Worthington Industries, Inc. is empowered to determine the issue prices, dividend rates, amounts payable upon liquidation and other terms of the preferred shares when issued. No preferred shares are issued or outstanding. Common Shares: On June 26, 2014, Worthington Industries, Inc. announced that on June 25, 2014, the Board of Directors of Worthington Industries, Inc. authorized the repurchase of up to 10,000,000 of our outstanding common shares. As of the end of the month of April, 2018 a total of 10,000,000 common shares had been repurchased under this authorization and, no further purchases may be made under this authorization. On September 27, 2017, the Board authorized the repurchase of up to an additional 6,828,855 common shares. The total number of common shares available for repurchase at May 31, 2018 was 6,500,000. During fiscal 2018, we repurchased 4,375,000 common shares having an aggregate cost of $204,267,000. During fiscal 2017, no common shares were repurchased under the then-existing authorization. During fiscal 2016, we repurchased 3,500,000 common shares having an aggregate cost of $99,847,000 under the then-existing authorization. Common shares available for repurchase under the authorization currently in effect may be purchased from time to time, with consideration given to the market price of the common shares, the nature of other investment opportunities, cash flows from operations, general economic conditions and other relevant considerations. Repurchases may be made on the open market or through privately negotiated transactions. On October 1, 2014, the Company amended its non-qualified deferred compensation plans for employees to require that any portion of a participant’s current account credited to the theoretical common share option, which reflects the fair value of the Company’s common shares with dividends reinvested, and any new contributions credited to the theoretical common share option remain credited to the theoretical common share option until distributed. For amounts credited to the theoretical common share option, payouts are required to be made in the form of whole common shares of the Company and cash in lieu of fractional common shares. As a result, we account for the deferred compensation obligation credited to the theoretical common share option within equity. The amounts recorded in equity totaled $1,218,000 and $1,259,000 during fiscal 2018 and fiscal 2017, respectively. Prior to October 1, 2014, participant accounts credited to the theoretical common share option were settled in cash and classified as a liability in the Company’s consolidated balance sheets.

Note I – Equity

Preferred Shares: The Worthington Industries, Inc. Amended Articles of Incorporation authorize two classes of preferred shares and their relative voting rights. The Board of Directors of Worthington Industries, Inc. is empowered to determine the issue prices, dividend rates, amounts payable upon liquidation and other terms of the preferred shares when issued. No preferred shares are issued or outstanding.

Common Shares: On June 26, 2014, Worthington Industries, Inc. announced that on June 25, 2014, the Board of Directors of Worthington Industries, Inc. authorized the repurchase of up to 10,000,000 of our outstanding common shares. As of the end of the month of April, 2018 a total of 10,000,000 common shares had been repurchased under this authorization and, no further purchases may be made under this authorization. On September 27, 2017, the Board authorized the repurchase of up to an additional 6,828,855 common shares. The total number of common shares available for repurchase at May 31, 2018 was 6,500,000.

During fiscal 2018, we repurchased 4,375,000 common shares having an aggregate cost of $204,267,000. During fiscal 2017, no common shares were repurchased under the then-existing authorization. During fiscal 2016, we repurchased 3,500,000 common shares having an aggregate cost of $99,847,000 under the then-existing authorization.

Common shares available for repurchase under the authorization currently in effect may be purchased from time to time, with consideration given to the market price of the common shares, the nature of other investment opportunities, cash flows from operations, general economic conditions and other relevant considerations. Repurchases may be made on the open market or through privately negotiated transactions.

On October 1, 2014, the Company amended its non-qualified deferred compensation plans for employees to require that any portion of a participant’s current account credited to the theoretical common share option, which reflects the fair value of the Company’s common shares with dividends reinvested, and any new contributions credited to the theoretical common share option remain credited to the theoretical common share option until distributed. For amounts credited to the theoretical common share option, payouts are required to be made in the form of whole common shares of the Company and cash in lieu of fractional common shares. As a result, we account for the deferred compensation obligation credited to the theoretical common share option within equity. The amounts recorded in equity totaled $1,218,000 and $1,259,000 during fiscal 2018 and fiscal 2017, respectively. Prior to October 1, 2014, participant accounts credited to the theoretical common share option were settled in cash and classified as a liability in the Company’s consolidated balance sheets.