Organization, Basis of Presentation and Significant Accounting Policies (Policies)	3 Months Ended
	Nov. 30, 2016
Accounting Policies [Abstract]
Consolidation, Policy	Our consolidated financial statements include the accounts of CHS and all of our wholly owned and majority owned subsidiaries. The effects of all significant intercompany transactions have been eliminated. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto for the year ended August 31, 2016, included in our Annual Report on Form 10-K, filed with the Securities and Exchange Commission (the "SEC").
Derivatives, Policy	Derivative Financial Instruments and Hedging Activities Our derivative instruments primarily consist of commodity and freight futures and forward contracts and, to a lesser degree, may include foreign currency and interest rate swap contracts. These contracts are economic hedges of price risk, but are not designated or accounted for as hedging instruments for accounting purposes, with the exception of certain interest rate swap contracts which are accounted for as cash flow hedges or fair value hedges. Derivative instruments are recorded on our Consolidated Balance Sheets at fair value. See Note 10, Derivative Financial Instruments and Hedging Activities and Note 11, Fair Value Measurements for additional information. Although we have certain netting arrangements for our exchange-traded futures and options contracts and certain over-the-counter ("OTC") contracts, we have elected to report our derivative instruments on a gross basis on our Consolidated Balance Sheets under Accounting Standards Codification ("ASC") Topic 210-20, Balance Sheet - Offsetting.
Major Maintenance Activities Policy	Major Maintenance Activities Within our Energy segment, major maintenance activities (“turnarounds”) are performed at our Laurel, Montana and McPherson, Kansas refineries regularly. Turnarounds are the planned and required shutdowns of refinery processing units, which include the replacement or overhaul of equipment that have experienced decreased efficiency in resource conversion. Because turnarounds are performed to extend the life, increase the capacity, and/or improve the safety or efficiency of refinery processing assets, we follow the deferral method of accounting for turnarounds. Expenditures for turnarounds are capitalized (deferred) when incurred and amortized on a straight-line basis over a period of 2 to 4 years, which is the estimated time lapse between turnarounds. Should the estimated period between turnarounds change, we may be required to amortize the remaining cost of the turnaround over a shorter period, which would result in higher depreciation and amortization costs. Capitalized turnaround costs are included in other assets (long-term) on our Consolidated Balance Sheets and amortization expense related to the capitalized turnaround costs is included in cost of goods sold in our Consolidated Statements of Operations. The selection of the deferral method, as opposed to expensing the turnaround costs when incurred, results in deferring recognition of the turnaround expenditures. The deferral method also results in the classification of the related cash outflows as investing activities in our Consolidated Statements of Cash Flows, whereas expensing these costs as incurred, would result in classifying the cash outflows as operating activities. Repair, maintenance and related labor costs are expensed as incurred and are included in operating cash flows.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Adopted In April 2015, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs, which simplifies the presentation of debt issuance costs. This ASU requires the presentation of debt issuance costs on the balance sheet as a deduction from the carrying amount of the related debt liability instead of a deferred financing cost. This ASU was effective for us beginning September 1, 2016, for our fiscal year 2017 and for interim periods within the fiscal year. As a result, $5.6 million of deferred issuance costs related to private placement debt and bank financing have been reclassified from other assets to long-term debt as of August 31, 2016. In August 2015, the FASB issued ASU No. 2015-15, Interest-Imputation of Interest (Subtopic 835-30): Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements, which codifies an SEC staff announcement that entities are permitted to defer and present debt issuance costs related to line of credit arrangements as assets. ASU 2015-15 was effective immediately. At August 31, 2016, we had unamortized deferred financing costs related to our line of credit arrangements, and we will continue to present debt issuance costs related to line of credit arrangements as an asset in our Consolidated Balance Sheets. Not Yet Adopted In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. This ASU is intended to reduce diversity in practice by adding or clarifying guidance on classification and presentation of changes in restricted cash on the statement of cash flows. This ASU is effective for us beginning September 1, 2018, for our fiscal year 2019 and for interim periods within that fiscal year. Early adoption is permitted, including in an interim period. The amendments in this ASU should be applied retrospectively to all periods presented. We are currently evaluating the impact the adoption will have on our consolidated financial statements. In October 2016, the FASB issued ASU No. 2016-16, Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory (Topic 740). This ASU is intended to improve the accounting for the income tax consequences of intra-entity transfers of assets other than inventory by requiring an entity to recognize the income tax consequences when a transfer occurs, instead of when an asset is sold to an outside party. The amendments in this ASU should be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. This ASU is effective for us beginning September 1, 2018, for our fiscal year 2019 and for interim periods within that fiscal year. Early adoption is permitted as of the beginning of an annual reporting period for which interim or annual financial statements have not been issued. We are currently evaluating the impact the adoption will have on our consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. This ASU is intended to reduce existing diversity in practice in how certain cash receipts and payments are presented and classified in the statement of cash flows. This ASU is effective for us beginning September 1, 2018, for our fiscal year 2019 and for interim periods within that fiscal year. Early adoption is permitted, including in an interim period. We are currently evaluating the impact the adoption will have on our consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The amendments in this ASU introduce a new approach, based on expected losses, to estimate credit losses on certain types of financial instruments. This ASU is intended to provide financial statement users with more decision-useful information about the expected credit losses associated with most financial assets measured at amortized cost and certain other instruments, including trade and other receivables, loans, held-to-maturity debt securities, net investments in leases, and off-balance-sheet credit exposures. Entities are required to apply the standard’s provisions as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. This ASU is effective for us beginning September 1, 2020, for our fiscal year 2021 and for interim periods within that fiscal year. We are currently evaluating the impact the adoption will have on our consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which replaces the existing guidance in ASC 840 - Leases. The amendments within this ASU introduce a lessee model requiring entities to recognize assets and liabilities for most leases, but continue recognizing the associated expenses in a manner similar to existing accounting guidance. This ASU does not make fundamental changes to existing lessor accounting; however, it does modify what constitutes a sales-type or direct financing lease and the related accounting, and aligns a number of the underlying principles with those of the new revenue standard, ASU No. 2014-09. The guidance also eliminates existing real estate-specific provisions and requires expanded qualitative and quantitative disclosures. Entities are required to apply the standard’s provisions using a modified retrospective approach at the beginning of the earliest comparative period presented in the year of adoption. This ASU is effective for us beginning September 1, 2019, for our fiscal year 2020 and for interim periods within that fiscal year. We are currently evaluating the impact the adoption will have on our consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers. The amendments within this ASU provide a single comprehensive model to be used in the accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This ASU includes a five step model for the recognition of revenue, including (1) identifying the contract with a customer, (2) identifying the performance obligations in the contract, (3) determining the transaction price, (4) allocating the transaction price to the performance obligations, and (5) recognizing revenue when (or as) an entity satisfies a performance obligation. This ASU also specifies the accounting for certain costs to obtain or fulfill a contract with a customer and requires expanded disclosures about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14 delaying the effective date of adoption for CHS to September 1, 2018. The FASB issued four subsequent ASUs in 2016 containing implementation guidance related to ASU No. 2014-09, including: ASU 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net), which is intended to improve the operability and understandability of the implementation guidance on principal versus agent considerations; ASU No. 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing, which is intended to clarify two aspects of Topic 606: identifying performance obligations and the licensing implementation guidance; ASU No. 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients, which contains certain provision and practical expedients in response to identified implementation issues; and ASU No. 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers, which contains certain corrections and clarifications to increase stakeholders’ awareness of the proposals and to expedite improvements. ASU No. 2014-09 permits the use of either a full or modified retrospective method upon adoption. Although early application as of the original date is permitted, we expect to adopt ASU No. 2014-09 and the related ASUs on September 1, 2018, in the first quarter of fiscal 2019. We are continuing to evaluate the effect this guidance will have on our consolidated financial statements, including potential impacts on the timing of revenue recognition and additional information that may be necessary for expanded disclosures regarding revenue. We have not yet selected a transition method nor have we determined the effect of the standard on our ongoing financial reporting.