Summary of Significant Accounting Policies (Policies)	3 Months Ended
Nov. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of PresentationThe accompanying Unaudited Condensed Consolidated Financial Statements of Schnitzer Steel Industries, Inc. (the “Company”) have been prepared pursuant to generally accepted accounting principles in the United States of America (“U.S. GAAP”) for interim financial information and the rules and regulations of the United States Securities and Exchange Commission (the “SEC”) for Form 10-Q, including Article 10 of Regulation S-X. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by U.S. GAAP. Certain information and note disclosures normally included in annual financial statements have been condensed or omitted pursuant to the rules and regulations of the SEC. In the opinion of management, all normal, recurring adjustments considered necessary for a fair statement have been included. Management suggests that these Unaudited Condensed Consolidated Financial Statements be read in conjunction with the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended August 31, 2018. The results for the three months ended November 30, 2018 and 2017 are not necessarily indicative of the results of operations for the entire fiscal year.
Accounting Changes	Accounting Changes As of the beginning of the first quarter of fiscal 2019, the Company adopted an accounting standards update initially issued in May 2014 that clarifies the principles for recognizing revenue from contracts with customers. The core principle of the new guidance is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration the entity expects to be entitled in exchange for those goods or services. The Company adopted the new revenue accounting standard using the modified retrospective approach, which requires recognition of the cumulative effect of initially applying the new requirements as an adjustment to the opening balance of retained earnings in the period of initial application. Adoption of the new requirements did not change the timing of revenue recognition for the Company compared to the previous guidance, and no cumulative-effect adjustment to the opening balance of retained earnings as of September 1, 2018 was recorded. The Company identified certain scrap purchase and sale arrangements for which it recognized revenue for the gross amount of consideration it expected to be entitled from the customer (as principal) under the previous revenue guidance, but for which under the new revenue standard it recognizes revenue as the net amount of consideration that it expects to retain after paying the scrap metal supplier (as agent). The foregoing change in the classification of the cost of scrap metal purchased under such arrangements has the effect of reducing the amount of revenue and cost of goods sold reported in the financial statements, while having no impact on net income. If the Company had continued using the accounting guidance in effect before the adoption of the new revenue accounting standard, its consolidated revenues for the three months ended November 30, 2018 would have been higher by approximately $6 million, or 1%, and its consolidated cost of goods sold would have been higher by the same amount. No other line items in the consolidated financial statements were materially impacted by adoption of the new requirements. Comparative prior period amounts and disclosures continue to be reported in accordance with guidance in effect prior to the date of adoption. See Note 7 - Revenue for the disclosures required under the new standard. As of the beginning of the first quarter of fiscal 2019, the Company adopted an accounting standards update that amends certain aspects of the reporting model for financial instruments. The most pertinent amendment to the Company is that an entity may choose to measure certain equity investments that do not have readily determinable fair values at cost minus impairment, plus or minus changes resulting from observable price changes. The amendments also require a qualitative assessment to identify impairment of equity investments without readily determinable fair values. Adoption of the requirements had no impact on the Company’s consolidated financial position, results of operations and cash flows.
Cash and Cash Equivalents	Cash and Cash EquivalentsCash and cash equivalents include short-term securities that are not restricted by third parties and have an original maturity date of 90 days or less. Included in accounts payable are book overdrafts representing outstanding checks in excess of funds on deposit of $35 million and $28 million as of November 30, 2018 and August 31, 2018, respectively.
Accounts Receivable, net	Accounts Receivable, net Accounts receivable represent amounts primarily due from customers on product and other sales. These accounts receivable, which are reduced by an allowance for doubtful accounts, are recorded at the invoiced amount and do not bear interest. Receivables from contracts with customers, net of an allowance for doubtful accounts, were $189 million and $164 million as of November 30, 2018 and August 31, 2018, respectively. The Company extends credit to customers under contracts containing customary and explicit payment terms, and payment is generally required within 30 days of shipment. Nonferrous export sales typically require a deposit prior to shipment. Historically, almost all of the Company’s ferrous export sales have been made with letters of credit. Domestic ferrous metal sales, nonferrous metal sales and finished steel sales are generally made on open account, and the majority of these sales are covered by credit insurance. The Company evaluates the collectibility of its accounts receivable based on a combination of factors, including whether sales were made pursuant to letters of credit or credit insurance is in place. In cases where management is aware of circumstances that may impair a customer’s ability to meet its financial obligations, management records a specific allowance against amounts due and reduces the receivable to the amount the Company believes will be collected. For all other customers, the Company maintains an allowance that considers the total receivables outstanding, historical collection rates and economic trends. Accounts are written off when all efforts to collect have been exhausted. Also included in accounts receivable are short-term advances to scrap metal suppliers used as a mechanism to acquire unprocessed scrap metal. The advances are generally repaid with scrap metal, as opposed to cash. Repayments of advances with scrap metal are treated as noncash operating activities in the Unaudited Condensed Consolidated Statements of Cash Flows and totaled $4 million and $3 million for the three months ended November 30, 2018 and 2017, respectively.
Other Assets	Prepaid Expenses The Company’s prepaid expenses totaled $17 million and $22 million as of November 30, 2018 and August 31, 2018, respectively, and consisted primarily of deposits on capital purchases, prepaid services and prepaid insurance. Other Assets The Company’s other assets, exclusive of prepaid expenses, consist primarily of receivables from insurers, an equity investment, debt issuance costs, and notes and other contractual receivables. Other assets are reported within either prepaid expenses and other current assets or other assets in the Unaudited Condensed Consolidated Balance Sheets based on their expected use either during or beyond the current operating cycle of one year from the reporting date. Receivables from insurers totaled $16 million and $36 million as of November 30, 2018 and August 31, 2018, respectively, with the decrease in the first quarter of fiscal 2019 resulting from the settlement of a contingent loss recorded during fiscal 2018 in connection with lawsuits arising from a motor vehicle collision for which the Company had insurance coverage. See “Contingencies – Other” in Note 5 – Commitments and Contingencies for further discussion of the contingent loss and subsequent settlements in fiscal 2019. The Company previously invested $6 million in a privately-held waste and recycling entity. The investment does not have a readily determinable fair value and, therefore, is carried at cost and adjusted for impairments and observable price changes. The investment is presented as part of the Auto and Metals Recycling (“AMR”) reportable segment and reported within other assets in the Unaudited Condensed Consolidated Balance Sheets. The carrying value of the investment was $6 million as of November 30, 2018 and August 31, 2018. The Company has not recorded any impairments or upward or downward adjustments to the carrying value of the investment since acquisition.
Investment	The Company previously invested $6 million in a privately-held waste and recycling entity. The investment does not have a readily determinable fair value and, therefore, is carried at cost and adjusted for impairments and observable price changes. The investment is presented as part of the Auto and Metals Recycling (“AMR”) reportable segment and reported within other assets in the Unaudited Condensed Consolidated Balance Sheets. The carrying value of the investment was $6 million as of November 30, 2018 and August 31, 2018. The Company has not recorded any impairments or upward or downward adjustments to the carrying value of the investment since acquisition.
Concentration of Credit Risk	Concentration of Credit RiskFinancial instruments that potentially subject the Company to significant concentration of credit risk consist primarily of cash and cash equivalents, accounts receivable, and notes and other contractual receivables. The majority of cash and cash equivalents is maintained with major financial institutions. Balances with these and certain other institutions exceeded the Federal Deposit Insurance Corporation insured amount of $250,000 as of November 30, 2018. Concentration of credit risk with respect to accounts receivable is limited because a large number of geographically diverse customers make up the Company’s customer base. The Company controls credit risk through credit approvals, limits, insurance, letters of credit or other collateral, cash deposits and monitoring procedures. The Company is exposed to a residual credit risk with respect to open letters of credit by virtue of the possibility of the failure of a bank providing a letter of credit. The Company had $84 million and $58 million of open letters of credit as of November 30, 2018 and August 31, 2018, respectively.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, an accounting standard was issued that will supersede the existing lease standard and require a lessee to recognize a lease liability and a lease asset on its balance sheet for all leases, including those classified as operating leases under the existing lease standard. The update also expands the required quantitative and qualitative disclosures surrounding leases. Additional updates have been issued since February 2016 amending aspects of the initial update, including providing an additional and optional transition method for adoption. This standard is effective for the Company beginning in fiscal 2020, including interim periods within that fiscal year. The Company expects to initially apply the requirements by recognizing a cumulative-effect adjustment to the opening balance of retained earnings, if any, in the period of adoption. The Company is in the process of analyzing its population of leases within the scope of the new accounting standard and documenting salient lease terms to support the initial and subsequent measurement of lease liabilities and lease assets. The Company is also assessing and implementing changes to its processes, systems, and internal controls as a result of the new guidance. The Company is evaluating the impact of adopting this standard on its financial position, results of operations, cash flows and disclosures, and it expects to recognize a material amount of lease assets and liabilities on its consolidated balance sheet upon adoption.
Revenue	Revenue The Company recognizes revenue upon satisfying its promises to transfer goods or services to customers under the terms of its contracts. Nearly all of these promises, referred to as performance obligations, consist of the transfer of physical goods, including ferrous and nonferrous recycled scrap metal, autobodies, auto parts, and finished steel products, to customers. These performance obligations are satisfied at the point in time the Company transfers control of the goods to the customer, which in nearly all cases is when title to and risk of loss of the goods transfer to the customer. The timing of transfer of title and risk of loss is dictated by customary or explicitly stated contract terms. For example, the Company recognizes revenue on partially loaded bulk shipments of ferrous recycled scrap metal when contractual terms support revenue recognition based on transfer of title and risk of loss. The significant majority of the Company’s sales involve transfer of control to the customer, and thus revenue recognition, before delivery to the customer’s destination. Shipping and handling activities that occur after a customer has obtained control of a good are accounted for as fulfillment costs rather than an additional promise in a contract. As such, freight revenue is recognized when control of the goods transfers to the customer, and freight expense is accrued when the related revenue is recognized. In certain regional markets, the Company enters into contracts whereby it arranges for, or brokers, the transfer of scrap material between scrap suppliers and end customers. For transactions in which the Company obtains substantive control of the scrap material before the goods are transferred to the end customer, for example by arranging for the processing or warehousing of the material, the Company recognizes revenue equal to the gross amount of the consideration it expects to receive from the customer (as principal). Alternatively, for transactions in which the Company does not obtain substantive control of the scrap material before the product is transferred to the end customer, the Company recognizes revenue equal to the net amount of the consideration it expects to retain after paying the supplier for the purchase of the scrap metal (as agent). The Company is the agent in the transaction for the substantial majority of brokerage arrangements. Nearly all of the Company’s sales contracts reflect market pricing at the time the contract is executed, are one year or less, and generally provide for shipment within 30 to 60 days after the price has been agreed upon with the customer. The Company’s retail auto parts sales are at listed prices and are recognized at the point of sale. The Company recognizes revenue based on contractually stated selling prices and quantities shipped, adjusted for estimated claims and discounts. Claims are customary in the recycled scrap metal industry and arise from variances in the quantity or quality of delivered products. Revenue adjustments may be required if the settlement of claims exceeds original estimates. Discounts offered to certain finished steel customers qualify as variable consideration as the discounts are contingent upon future events. Variable consideration arising from discounts is recognized upon the transfer of finished steel products to customers based upon either the expected value or the most likely amount and was not material for the three months ended November 30, 2018. The Company experiences very few sales returns and, therefore, no material provisions for returns have been made when sales are recognized. During the three months ended November 30, 2018, revenue adjustments related to performance obligations that were satisfied in previous periods were not material.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Nov. 30, 2018

Basis of PresentationThe accompanying Unaudited Condensed Consolidated Financial Statements of Schnitzer Steel Industries, Inc. (the “Company”) have been prepared pursuant to generally accepted accounting principles in the United States of America (“U.S. GAAP”) for interim financial information and the rules and regulations of the United States Securities and Exchange Commission (the “SEC”) for Form 10-Q, including Article 10 of Regulation S-X. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by U.S. GAAP. Certain information and note disclosures normally included in annual financial statements have been condensed or omitted pursuant to the rules and regulations of the SEC. In the opinion of management, all normal, recurring adjustments considered necessary for a fair statement have been included. Management suggests that these Unaudited Condensed Consolidated Financial Statements be read in conjunction with the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended August 31, 2018. The results for the three months ended November 30, 2018 and 2017 are not necessarily indicative of the results of operations for the entire fiscal year.

Accounting Changes

As of the beginning of the first quarter of fiscal 2019, the Company adopted an accounting standards update initially issued in May 2014 that clarifies the principles for recognizing revenue from contracts with customers. The core principle of the new guidance is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration the entity expects to be entitled in exchange for those goods or services. The Company adopted the new revenue accounting standard using the modified retrospective approach, which requires recognition of the cumulative effect of initially applying the new requirements as an adjustment to the opening balance of retained earnings in the period of initial application. Adoption of the new requirements did not change the timing of revenue recognition for the Company compared to the previous guidance, and no cumulative-effect adjustment to the opening balance of retained earnings as of September 1, 2018 was recorded. The Company identified certain scrap purchase and sale arrangements for which it recognized revenue for the gross amount of consideration it expected to be entitled from the customer (as principal) under the previous revenue guidance, but for which under the new revenue standard it recognizes revenue as the net amount of consideration that it expects to retain after paying the scrap metal supplier (as agent). The foregoing change in the classification of the cost of scrap metal purchased under such arrangements has the effect of reducing the amount of revenue and cost of goods sold reported in the financial statements, while having no impact on net income. If the Company had continued using the accounting guidance in effect before the adoption of the new revenue accounting standard, its consolidated revenues for the three months ended November 30, 2018 would have been higher by approximately $6 million, or 1%, and its consolidated cost of goods sold would have been higher by the same amount. No other line items in the consolidated financial statements were materially impacted by adoption of the new requirements. Comparative prior period amounts and disclosures continue to be reported in accordance with guidance in effect prior to the date of adoption. See Note 7 - Revenue for the disclosures required under the new standard.

As of the beginning of the first quarter of fiscal 2019, the Company adopted an accounting standards update that amends certain aspects of the reporting model for financial instruments. The most pertinent amendment to the Company is that an entity may choose to measure certain equity investments that do not have readily determinable fair values at cost minus impairment, plus or minus changes resulting from observable price changes. The amendments also require a qualitative assessment to identify impairment of equity investments without readily determinable fair values. Adoption of the requirements had no impact on the Company’s consolidated financial position, results of operations and cash flows.

Cash and Cash Equivalents

Cash and Cash EquivalentsCash and cash equivalents include short-term securities that are not restricted by third parties and have an original maturity date of 90 days or less. Included in accounts payable are book overdrafts representing outstanding checks in excess of funds on deposit of $35 million and $28 million as of November 30, 2018 and August 31, 2018, respectively.

Accounts Receivable, net

Accounts receivable represent amounts primarily due from customers on product and other sales. These accounts receivable, which are reduced by an allowance for doubtful accounts, are recorded at the invoiced amount and do not bear interest. Receivables from contracts with customers, net of an allowance for doubtful accounts, were $189 million and $164 million as of November 30, 2018 and August 31, 2018, respectively. The Company extends credit to customers under contracts containing customary and explicit payment terms, and payment is generally required within 30 days of shipment. Nonferrous export sales typically require a deposit

prior to shipment. Historically, almost all of the Company’s ferrous export sales have been made with letters of credit. Domestic ferrous metal sales, nonferrous metal sales and finished steel sales are generally made on open account, and the majority of these sales are covered by credit insurance.

The Company evaluates the collectibility of its accounts receivable based on a combination of factors, including whether sales were made pursuant to letters of credit or credit insurance is in place. In cases where management is aware of circumstances that may impair a customer’s ability to meet its financial obligations, management records a specific allowance against amounts due and reduces the receivable to the amount the Company believes will be collected. For all other customers, the Company maintains an allowance that considers the total receivables outstanding, historical collection rates and economic trends. Accounts are written off when all efforts to collect have been exhausted.

Also included in accounts receivable are short-term advances to scrap metal suppliers used as a mechanism to acquire unprocessed scrap metal. The advances are generally repaid with scrap metal, as opposed to cash. Repayments of advances with scrap metal are treated as noncash operating activities in the Unaudited Condensed Consolidated Statements of Cash Flows and totaled $4 million and $3 million for the three months ended November 30, 2018 and 2017, respectively.

Other Assets

Prepaid Expenses

The Company’s prepaid expenses totaled $17 million and $22 million as of November 30, 2018 and August 31, 2018, respectively, and consisted primarily of deposits on capital purchases, prepaid services and prepaid insurance.

Other Assets

The Company’s other assets, exclusive of prepaid expenses, consist primarily of receivables from insurers, an equity investment, debt issuance costs, and notes and other contractual receivables. Other assets are reported within either prepaid expenses and other current assets or other assets in the Unaudited Condensed Consolidated Balance Sheets based on their expected use either during or beyond the current operating cycle of one year from the reporting date. Receivables from insurers totaled $16 million and $36 million as of November 30, 2018 and August 31, 2018, respectively, with the decrease in the first quarter of fiscal 2019 resulting from the settlement of a contingent loss recorded during fiscal 2018 in connection with lawsuits arising from a motor vehicle collision for which the Company had insurance coverage. See “Contingencies – Other” in Note 5 – Commitments and Contingencies for further discussion of the contingent loss and subsequent settlements in fiscal 2019.

The Company previously invested $6 million in a privately-held waste and recycling entity. The investment does not have a readily determinable fair value and, therefore, is carried at cost and adjusted for impairments and observable price changes. The investment is presented as part of the Auto and Metals Recycling (“AMR”) reportable segment and reported within other assets in the Unaudited Condensed Consolidated Balance Sheets. The carrying value of the investment was $6 million as of November 30, 2018 and August 31, 2018. The Company has not recorded any impairments or upward or downward adjustments to the carrying value of the investment since acquisition.

Investment

Concentration of Credit Risk

Concentration of Credit RiskFinancial instruments that potentially subject the Company to significant concentration of credit risk consist primarily of cash and cash equivalents, accounts receivable, and notes and other contractual receivables. The majority of cash and cash equivalents is maintained with major financial institutions. Balances with these and certain other institutions exceeded the Federal Deposit Insurance Corporation insured amount of $250,000 as of November 30, 2018. Concentration of credit risk with respect to accounts receivable is limited because a large number of geographically diverse customers make up the Company’s customer base. The Company controls credit risk through credit approvals, limits, insurance, letters of credit or other collateral, cash deposits and monitoring procedures. The Company is exposed to a residual credit risk with respect to open letters of credit by virtue of the possibility of the failure of a bank providing a letter of credit. The Company had $84 million and $58 million of open letters of credit as of November 30, 2018 and August 31, 2018, respectively.

Recent Accounting Pronouncements

In February 2016, an accounting standard was issued that will supersede the existing lease standard and require a lessee to recognize a lease liability and a lease asset on its balance sheet for all leases, including those classified as operating leases under the existing lease standard. The update also expands the required quantitative and qualitative disclosures surrounding leases. Additional updates have been issued since February 2016 amending aspects of the initial update, including providing an additional and optional transition method for adoption. This standard is effective for the Company beginning in fiscal 2020, including interim periods within that fiscal year. The Company expects to initially apply the requirements by recognizing a cumulative-effect adjustment to the opening balance of retained earnings, if any, in the period of adoption. The Company is in the process of analyzing its population of leases within the scope of the new accounting standard and documenting salient lease terms to support the initial and subsequent

measurement of lease liabilities and lease assets. The Company is also assessing and implementing changes to its processes, systems, and internal controls as a result of the new guidance. The Company is evaluating the impact of adopting this standard on its financial position, results of operations, cash flows and disclosures, and it expects to recognize a material amount of lease assets and liabilities on its consolidated balance sheet upon adoption.

Revenue

The Company recognizes revenue upon satisfying its promises to transfer goods or services to customers under the terms of its contracts. Nearly all of these promises, referred to as performance obligations, consist of the transfer of physical goods, including ferrous and nonferrous recycled scrap metal, autobodies, auto parts, and finished steel products, to customers. These performance obligations are satisfied at the point in time the Company transfers control of the goods to the customer, which in nearly all cases is when title to and risk of loss of the goods transfer to the customer. The timing of transfer of title and risk of loss is dictated by customary or explicitly stated contract terms. For example, the Company recognizes revenue on partially loaded bulk shipments of ferrous recycled scrap metal when contractual terms support revenue recognition based on transfer of title and risk of loss. The significant majority of the Company’s sales involve transfer of control to the customer, and thus revenue recognition, before delivery to the customer’s destination. Shipping and handling activities that occur after a customer has obtained control of a good are accounted for as fulfillment costs rather than an additional promise in a contract. As such, freight revenue is recognized when control of the goods transfers to the customer, and freight expense is accrued when the related revenue is recognized.

In certain regional markets, the Company enters into contracts whereby it arranges for, or brokers, the transfer of scrap material between scrap suppliers and end customers. For transactions in which the Company obtains substantive control of the scrap material before the goods are transferred to the end customer, for example by arranging for the processing or warehousing of the material, the Company recognizes revenue equal to the gross amount of the consideration it expects to receive from the customer (as principal). Alternatively, for transactions in which the Company does not obtain substantive control of the scrap material before the product is transferred to the end customer, the Company recognizes revenue equal to the net amount of the consideration it expects to retain after paying the supplier for the purchase of the scrap metal (as agent). The Company is the agent in the transaction for the substantial majority of brokerage arrangements.

Nearly all of the Company’s sales contracts reflect market pricing at the time the contract is executed, are one year or less, and generally provide for shipment within 30 to 60 days after the price has been agreed upon with the customer. The Company’s retail auto parts sales are at listed prices and are recognized at the point of sale.

The Company recognizes revenue based on contractually stated selling prices and quantities shipped, adjusted for estimated claims and discounts. Claims are customary in the recycled scrap metal industry and arise from variances in the quantity or quality of delivered products. Revenue adjustments may be required if the settlement of claims exceeds original estimates. Discounts offered to certain finished steel customers qualify as variable consideration as the discounts are contingent upon future events. Variable consideration arising from discounts is recognized upon the transfer of finished steel products to customers based upon either the expected value or the most likely amount and was not material for the three months ended November 30, 2018. The Company experiences very few sales returns and, therefore, no material provisions for returns have been made when sales are recognized. During the three months ended November 30, 2018, revenue adjustments related to performance obligations that were satisfied in previous periods were not material.