Basis of Presentation (Policies)	3 Months Ended
Basis of Presentation (Policies)	Aug. 31, 2016
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards In February 2015, amended accounting guidance was issued that revised consolidation requirements in order to provide financial statement users with a more useful presentation of an entity’s economic and operational results. The amended guidance revises the consolidation requirements for limited partnerships, the considerations surrounding the primary beneficiary determination and the consolidation of certain investment funds and is effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. The Company adopted this amended guidance on a prospective basis effective June 1, 2016. The adoption of this guidance did not impact our financial position or results of operations. In April 2015, amended accounting guidance was issued that requires debt issuance costs related to a recognized debt liability to be presented in the balance sheet as a direct deduction from the carrying amount of the corresponding debt liability itself. The amended guidance does not apply to line-of-credit arrangements. Accordingly, issuance costs related to line-of-credit arrangements will continue to be presented as an asset and amortized ratably over the term of the arrangement. The amended guidance is effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. The Company adopted this guidance on a retrospective basis effective June 1, 2016. As a result, debt issuance costs totaling $2,405,000 and $2,491,000 as of August 31, 2016 and May 31, 2016, respectively, have been presented as a component of the carrying amount of long-term debt reported in our consolidated balance sheets. These amounts were previously capitalized and reported within other assets. In September 2015, amended accounting guidance was issued regarding adjustments to provisional amounts recorded in conjunction with a business combination. The amended guidance requires the acquirer to recognize adjustments to provisional amounts identified during the measurement period in the reporting period in which such adjustments are identified, rather than retrospectively adjusting previously reported amounts. The amended guidance is effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. The Company adopted this amended guidance on a prospective basis effective June 1, 2016. The adoption of this guidance did not impact our financial position or results of operations. In March 2016, amended accounting guidance was issued that simplifies the accounting for share-based payments. The amended guidance impacts several aspects of the accounting for share-based payment transactions, including the income tax consequences, forfeitures, statutory withholding requirements, and classification in the statement of cash flows. The Company early adopted this guidance during the fourth quarter of fiscal 2016. As required for early adoption in an interim period, all adjustments have been reflected as of the beginning of fiscal 2016. Accordingly, income tax expense for the three months ended August 31, 2015 has been restated to reflect excess tax benefits associated with share-based payments totaling $558,000 in current income tax expense, rather than in paid-in capital.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In May 2014, amended accounting guidance was issued that replaces most existing revenue recognition guidance under U.S. GAAP. The amended guidance requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. Subsequently, additional guidance was issued on several areas including guidance intended to improve the operability and understandability of the implementation of principal versus agent considerations and clarifications on the identification of performance obligations and implementation of guidance related to licensing. The amended guidance is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. We are in the process of evaluating the effect this guidance will have on our consolidated financial position and results of operations. The amended guidance permits the use of either the retrospective or cumulative effect transition method. We have not selected a transition method nor have we determined the effect of the amended guidance on our ongoing financial reporting. In July 2015, amended accounting guidance was issued regarding the measurement of inventory. The amended guidance requires that inventory accounted for under the first-in, first-out (FIFO) or average cost methods be measured at the lower of cost and net realizable value, where net realizable value represents the estimated selling price of inventory in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The amended guidance has no impact on inventory accounted for under the last-in, first-out (LIFO) or retail inventory methods. The amended guidance is effective prospectively for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted as of the beginning of an interim or annual reporting period. We do not expect the adoption of this amended accounting guidance to have a material impact on our financial position or results of operations. In February 2016, amended accounting guidance was issued that replaces most existing lease accounting guidance under U.S. GAAP. Among other changes, the amended guidance requires that lease assets and liabilities be recognized on the balance sheet by lessees for those leases classified as operating leases under previous guidance. The amended 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. We are in the process of evaluating the effect this guidance will have on our consolidated financial position and results of operations, and we have not determined the effect of the amended guidance on our ongoing financial reporting. In March 2016, amended accounting guidance was issued regarding derivative instruments designated as hedging instruments. The amended guidance clarifies that a change in the counterparty to such a hedging instrument does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The amended guidance is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted, and the change may be applied either prospectively or retrospectively. We do not expect the adoption of this amended accounting guidance to have a material impact on our financial position or results of operations. 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, and we have not determined the effect of the amended guidance on our ongoing financial reporting. In August 2016, amended accounting guidance was issued to clarify the proper cash flow presentation of certain specific types of cash payments and cash receipts. The amended guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. 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 amended guidance on our ongoing financial reporting.
Economic (Non-designated) Hedges	Economic (Non-designated) Hedges We enter into foreign currency contracts to manage our foreign currency exchange rate exposure related to inter-company and financing transactions that do not meet the requirements for hedge accounting treatment. We also enter into certain commodity contracts that do not qualify for hedge accounting treatment. Accordingly, these derivative instruments are adjusted to current market value at the end of each period through earnings.
Cash Flow Hedges
Cash Flow Hedges	Cash Flow Hedges We enter into derivative instruments to hedge our exposure to changes in cash flows attributable to interest rates and commodity price fluctuations associated with certain forecasted transactions. These derivative instruments are designated and qualify as cash flow hedges. Accordingly, the effective portion of the gain or loss on the derivative instrument is reported as a component of OCI and reclassified into earnings in the same financial statement caption associated with the forecasted transaction and in the same period during which the hedged transaction affects earnings. The ineffective portion of the gain or loss on the derivative instrument is recognized in earnings immediately.