Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The accompanying unaudited consolidated condensed financial statements include the accounts of SIFCO Industries, Inc. and its wholly-owned subsidiaries (the "Company"). All significant intercompany accounts and transactions have been eliminated. The U.S. dollar is the functional currency for all of the Company’s U.S. operations and its Irish subsidiaries. For these operations, all gains and losses from completed currency transactions are included in income currently. The functional currency for the Company's other non-U.S. subsidiaries is the Euro. Assets and liabilities are translated into U.S. dollars at the rates of exchange at the end of the period, and revenues and expenses are translated using average rates of exchange for the period. Foreign currency translation adjustments are reported as a component of accumulated other comprehensive loss in the unaudited consolidated condensed financial statements. These unaudited consolidated condensed financial statements should be read in conjunction with the consolidated financial statements and related notes included in the Company’s fiscal 2017 Annual Report on Form 10-K. The year-end consolidated balance sheet data was derived from audited financial statements and disclosures required by accounting principles generally accepted accounting in the United States ("U.S."). The results of operations for any interim period are not necessarily indicative of the results to be expected for other interim periods or the full year.
Income taxes	Income taxes On December 22, 2017, the U.S. enacted the Tax Cut and Jobs Act (the "Act") which, among other items, reduces the U.S. corporate tax rate effective January 1, 2018 from 35% to 21%, creates a participation exemption regime for future distributions of foreign earnings, imposes a one-time transition tax on a taxpayer’s foreign subsidiaries’ earnings not previously subject to U.S. taxation and creates new taxes on certain foreign-sourced earnings. On the same day of the Act, the Securities and Exchange Commission (the "SEC") issued Staff Bulletin 118 ("SAB 118"). SAB 118 expresses views of the SEC regarding ASC Topic 740, Income taxes ("ASC 740") in the reporting period that includes the enactment date of the Act. The SEC staff issuing SAB 118 recognized that a company’s review of certain income tax effects of the Act may be incomplete at the time the financial statements are issued for the reporting period that includes the enactment date, including interim periods therein. If a company does not have the necessary information available, prepared or analyzed for certain income tax effects of the Act, SAB 118 allows a company to report provisional numbers and adjust those amounts during the measurement period not to extend beyond one year from the day of enactment. The Act also includes provisions for Global Intangible Low-Taxed Income (“GILTI”) wherein taxes on foreign income are imposed in excess of a deemed return on tangible assets of foreign corporations. This income will effectively be taxed at a 10.5% tax rate in general. Because of the complexity of the new provisions, the Company is continuing to evaluate how the provisions will be accounted for under the U.S. generally accepted accounting principles wherein companies are allowed to make an accounting policy election to either (i) account for GILTI as a component of tax expense in the period in which the Company is subject to the rules (the “period cost method”), or (ii) account for GILTI in the Company’s measurement of deferred taxes (the “deferred method”). Currently, the Company has not elected a method and will only do so after its completion of the analysis of the GILTI provisions and its election method will depend, in part, on analyzing its global income to determine whether the Company expects to have future material U.S. inclusions in its taxable income related to GILTI and, if so, the impact that is expected.
Net Loss per Share	Net Loss per Share The Company’s net loss per basic share has been computed based on the weighted-average number of common shares outstanding.
Derivative Financial Instruments	Derivative Financial Instruments The Company entered into an interest rate swap agreement on March 29, 2016 to reduce risk related to variable-rate debt, which was subject to changes in market rates of interest. The interest rate swap was designated as a cash flow hedge.
Impact of Recently Issued Accounting Standards and Recently Adopted Accounting Standards	Impact of Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-02, “Leases (Topic 842).” This ASU requires lessees to recognize a lease liability and a right-of-use asset on the balance sheet and aligns many of the underlying principles of the new lessor model with those in Accounting Standards Codification Topic 606, Revenue from Contracts with Customers. The standard requires a modified retrospective transition for capital and operating leases existing at or entered into after the beginning of the earliest comparative period presented in the financial statements, but it does not require transition accounting for leases that expire prior to the date of initial adoption. The ASU is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the requirements of ASU 2016-02 and anticipates that the adoption will impact the consolidated condensed balance sheets due to the recognition of the right-to-use asset and lease liability related to its current operating leases. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 completes the joint effort by the FASB and International Accounting Standards Board to improve financial reporting by creating common revenue recognition guidance for GAAP and International Financial Reporting Standards. In March 2016, the FASB issued ASU 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net).” The ASU 2016-08 clarifies the implementation guidance on principal versus agent considerations. In April 2016, the FASB issued ASU 2016-10, “Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing.” This ASU 2016-10 clarifies the implementation guidance on identifying performance obligations. These ASUs, along with subsequent updates, apply to all companies that enter into contracts with customers to transfer goods or services, and are effective for public entities for interim and annual reporting periods beginning after December 15, 2017. The Company will adopt the new guidance on October 1, 2018. The Company is executing a bottom up approach to analyze the standard's impact on its revenues by looking at historical policies and practices and identifying the differences from applying the new standard to its revenue streams. The Company has determined that many of its long-term agreements contain variable consideration clauses and is in the process of quantifying the impact to its consolidated financial statements. In addition, some of the Company's agreements have clauses which may require the Company to recognize revenue over time. The majority of the Company's current revenue is recognized at a point-in-time. As such, SIFCO continues to evaluate the impact of the standard on its financial reporting, disclosures and related systems and internal controls. The Company has engaged a third party to assist with its efforts. F. Recently Adopted Accounting Standards In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, which amends existing guidance related to accounting for employee share-based payments affecting the income tax consequences of awards, classification of awards as equity or liabilities, and classification on the statement of cash flows. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, and early adoption is permitted. ASU 2016-09 was adopted by the Company effective October 1, 2017. This guidance requires all excess tax benefits and tax deficiencies be recognized as income tax expense or benefit in the income statement and also requires a policy election to either estimate the number of awards that are expected to vest or account for forfeitures when they occur. The Company changed its policy to recognize the impact of forfeitures when they actually occur. There was no impact to the consolidated condensed financial statements as of October 1, 2017. Also, this guidance requires cash paid by an employer when directly withholding shares for tax withholding purposes to be classified in the consolidated condensed statement of cash flows as a financing activity, which differs from the Company's previous method of classification of such cash payments as an operating activity. The Company applied this provision retrospectively, and for the first quarter of fiscal 2017, the impact between operating activities to financing activities was nominal. This guidance also requires the tax effects of exercised or vested awards to be treated as discrete items in the reporting period in which they occur, which was applied prospectively, beginning October 1, 2017 by the Company. Due to the Company having recorded a domestic valuation allowance, the tax impact upon adoption of this ASU was not material to the consolidated condensed financial statements. Lastly, the guidance requires that excess tax benefits should be classified along with other income tax cash flows as an operating activity on the statement of cash flows, which differs from the Company’s historical classification of excess tax benefits as cash inflows from financing activities. The Company elected to apply this provision using the prospective transition method. In July 2015, the FASB issued ASU No. 2015-11, Simplifying the Measurement of Inventory, which provides new guidance to simplify the measurement of inventory valuation at the lower of cost or net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The adoption of this ASU in the first quarter ended December 31, 2017 had no impact on the Company's consolidated condensed financial statements.

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.