Organization, Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
May 31, 2018
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, 2017, included in our Annual Report on Form 10-K, filed with the Securities and Exchange Commission (the "SEC").
Recent Accounting Pronouncements	Recent Accounting Pronouncements Adopted In October 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("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. This ASU is effective for periods beginning after December 15, 2017; however, early adoption of this ASU is permitted during the first interim period if an entity issues interim financial statements and 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. We elected to early adopt ASU No. 2016-16 during the first quarter of fiscal 2018. The adoption did not have a material impact on our consolidated financial statements. Not Yet Adopted In February 2018, the FASB issued ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220). Under existing U.S. GAAP the effects of changes in tax rates and laws on deferred tax balances are recorded as a component of income tax expense in the period in which the law was enacted. When deferred tax balances related to items originally recorded in accumulated other comprehensive income are adjusted, certain tax effects become stranded in accumulated other comprehensive income. The amendments in ASU 2018-02 allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 (the "Tax Act"). The amendments in this ASU also require certain disclosures about stranded tax effects. This ASU is effective for us beginning September 1, 2019, for our fiscal year 2020 and for interim periods within that fiscal year. Early adoption in any period is permitted. The Company’s provisional adjustments recorded to account for the impact of the Tax Cuts and Jobs Act resulted in stranded tax effects. We are currently evaluating the timing and impact of adopting ASU 2018-02. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. This ASU is intended to improve the financial reporting of hedging relationships to better represent the economic results of an entity’s risk management activities in its financial statements and make certain improvements to simplify the application of the hedge accounting guidance. The amendments in this ASU will make more financial and nonfinancial hedging strategies eligible for hedge accounting, amend the presentation and disclosure requirements and change how entities assess effectiveness. Entities are required to apply this ASU'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, 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 March 2017, the FASB issued ASU No. 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Costs and Net Postretirement Benefit Cost. This ASU changes the presentation of net periodic pension cost and net periodic postretirement benefit cost in the Consolidated Statements of Operations. This ASU requires that the service cost component be included in the same line item as other compensation costs arising from services rendered by the employees during the period. The other components of net periodic benefit cost should be presented in the Consolidated Statements of Operations separately outside of operating income if that subtotal is presented. Additionally, only service cost may be capitalized in assets. This ASU is effective for us beginning September 1, 2018, for our fiscal year 2019 and for interim periods within that fiscal year. The guidance on the presentation of the components of net periodic benefit cost in the Consolidated Statements of Operations should be applied retrospectively and the guidance regarding the capitalization of the service cost component in assets should be applied prospectively. The adoption of this amended guidance is not expected to have a material impact on our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. The amendments within this ASU narrow the existing definition of a business and provide a more robust framework for evaluating whether a transaction should be accounted for as an acquisition (or disposal) of assets or a business. The definition of a business impacts various areas of accounting, including acquisitions, disposals and goodwill. Under the new guidance, fewer acquisitions are expected to be considered businesses. 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 and the guidance should be applied prospectively to transactions following the adoption date. The adoption of this amended guidance is not expected to have a material impact on our consolidated financial statements. 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 Consolidated Statements 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. The adoption of this amended guidance is not expected to have a material impact on our Consolidated Statements of Cash Flows. 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 Consolidated Statements 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. We are currently evaluating the impact the adoption will have on our Consolidated Statement of Cash Flows. 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 this ASU’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 Accounting Standards Codification ("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 is effective for us beginning September 1, 2019, for our fiscal year 2020 and for interim periods within that fiscal year. We have initiated our assessment of the new lease standard, including the utilization of surveys to gather more information about existing leases and the implementation of a new lease software to improve the collection, maintenance, and aggregation of lease data necessary for the expanded reporting and disclosure requirements under the new lease standard. It is expected that the primary impact upon adoption will be the recognition, on a discounted basis, of our minimum commitments under noncancelable operating leases as right of use assets and obligations on our Consolidated Balance Sheets. This will result in a significant increase in assets and liabilities recorded on our Consolidated Balance Sheets. Although we expect the new lease guidance to have a material impact on our Consolidated Balance Sheets, we are continuing to evaluate the method of adoption and the extent of potential impacts on our consolidated financial statements, processes, and internal controls. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). The amendments within this ASU, as well as within additional clarifying ASUs issued by the FASB, 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. The new revenue recognition guidance 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. The adoption of the new revenue recognition guidance will require expanded disclosures in our consolidated financial statements including quantitative disclosure of revenues that fall within and outside the scope of the new revenue recognition guidance. Certain revenue streams are expected to fall within the scope of the new revenue recognition guidance; however, a substantial portion of our revenue falls outside the scope of the new revenue recognition guidance and will continue to follow existing guidance, primarily ASC 815, Derivatives and Hedging. We have completed an initial assessment of our revenue streams and do not believe that the new revenue recognition guidance will have a material impact on our consolidated financial statements. We will complete the final phase of our revenue recognition implementation project during the fourth quarter of fiscal 2018, including the finalization of our revenue recognition accounting policies, expanded disclosures, and position papers. We will adopt ASU No. 2014-09 and the related ASUs using the modified retrospective method on September 1, 2018, in the first quarter of fiscal 2019.

Recent Accounting Pronouncements

Adopted

In October 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("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. This ASU is effective for periods beginning after December 15, 2017; however, early adoption of this ASU is permitted during the first interim period if an entity issues interim financial statements and 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. We elected to early adopt ASU No. 2016-16 during the first quarter of fiscal 2018. The adoption did not have a material impact on our consolidated financial statements.

Not Yet Adopted

In February 2018, the FASB issued ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220). Under existing U.S. GAAP the effects of changes in tax rates and laws on deferred tax balances are recorded as a component of income tax expense in the period in which the law was enacted. When deferred tax balances related to items originally recorded in accumulated other comprehensive income are adjusted, certain tax effects become stranded in accumulated other comprehensive income. The amendments in ASU 2018-02 allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 (the "Tax Act"). The amendments in this ASU also require certain disclosures about stranded tax effects. This ASU is effective for us beginning September 1, 2019, for our fiscal year 2020 and for interim periods within that fiscal year. Early adoption in any period is permitted. The Company’s provisional adjustments recorded to account for the impact of the Tax Cuts and Jobs Act resulted in stranded tax effects. We are currently evaluating the timing and impact of adopting ASU 2018-02.

In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. This ASU is intended to improve the financial reporting of hedging relationships to better represent the economic results of an entity’s risk management activities in its financial statements and make certain improvements to simplify the application of the hedge accounting guidance. The amendments in this ASU will make more financial and nonfinancial hedging strategies eligible for hedge accounting, amend the presentation and disclosure requirements and change how entities assess effectiveness. Entities are required to apply this ASU'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, 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 March 2017, the FASB issued ASU No. 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Costs and Net Postretirement Benefit Cost. This ASU changes the presentation of net periodic pension cost and net periodic postretirement benefit cost in the Consolidated Statements of Operations. This ASU requires that the service cost component be included in the same line item as other compensation costs arising from services rendered by the employees during the period. The other components of net periodic benefit cost should be presented in the Consolidated Statements of Operations separately outside of operating income if that subtotal is presented. Additionally, only service cost may be capitalized in assets. This ASU is effective for us beginning September 1, 2018, for our fiscal year 2019 and for interim periods within that fiscal year. The guidance on the presentation of the components of net periodic benefit cost in the Consolidated Statements of Operations should be applied retrospectively and the guidance regarding the capitalization of the service cost component in assets should be applied prospectively. The adoption of this amended guidance is not expected to have a material impact on our consolidated financial statements.

In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. The amendments within this ASU narrow the existing definition of a business and provide a more robust framework for evaluating whether a transaction should be accounted for as an acquisition (or disposal) of assets or a business. The definition of a business impacts various areas of accounting, including acquisitions, disposals and goodwill. Under the new guidance, fewer acquisitions are expected to be considered businesses. 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 and the guidance should be applied prospectively to transactions following the adoption date. The adoption of this amended guidance is not expected to have a material impact on our consolidated financial statements.

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 Consolidated Statements 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. The adoption of this amended guidance is not expected to have a material impact on our Consolidated Statements of Cash Flows.

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 Consolidated Statements 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. We are currently evaluating the impact the adoption will have on our Consolidated Statement of Cash Flows.

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 this ASU’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 Accounting Standards Codification ("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 is effective for us beginning September 1, 2019, for our fiscal year 2020 and for interim periods within that fiscal year. We have initiated our assessment of the new lease standard, including the utilization of surveys to gather more information about existing leases and the implementation of a new lease software to improve the collection, maintenance, and aggregation of lease data necessary for the expanded reporting and disclosure requirements under the new lease standard. It is expected that the primary impact upon adoption will be the recognition, on a discounted basis, of our minimum commitments under noncancelable operating leases as right of use assets and obligations on our Consolidated Balance Sheets. This will result in a significant increase in assets and liabilities recorded on our Consolidated Balance Sheets. Although we expect the new lease guidance to have a material impact on our Consolidated Balance Sheets, we are continuing to evaluate the method of adoption and the extent of potential impacts on our consolidated financial statements, processes, and internal controls.

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). The amendments within this ASU, as well as within additional clarifying ASUs issued by the FASB, 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. The new revenue recognition guidance 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. The adoption of the new revenue recognition guidance will require expanded disclosures in our consolidated financial statements including quantitative disclosure of revenues that fall within and outside the scope of the new revenue recognition guidance. Certain revenue streams are expected to fall within the scope of the new revenue recognition guidance; however, a substantial portion of our revenue falls outside the scope of the new revenue recognition guidance and will continue to follow existing guidance, primarily ASC 815, Derivatives and Hedging. We have completed an initial assessment of our revenue streams and do not believe that the new revenue recognition guidance will have a material impact on our consolidated financial statements. We will complete the final phase of our revenue recognition implementation project during the fourth quarter of fiscal 2018, including the finalization of our revenue recognition accounting policies, expanded disclosures, and position papers. We will adopt ASU No. 2014-09 and the related ASUs using the modified retrospective method on September 1, 2018, in the first quarter of fiscal 2019.