Presentation of Condensed Consolidated Financial Statements (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Accounting	Presentation During interim periods, we follow the accounting policies set forth in our Annual Report on Form 10-K for the fiscal year ended December 31, 2017 (the “2017 Annual Report on Form 10-K”) and apply appropriate interim financial reporting standards for a fair statement of our operating results and financial position in conformity with accounting principles generally accepted in the United States of America, as codified by the Financial Accounting Standards Board (“FASB”) in the Accounting Standards Codification (“ASC”) (referred to herein as “U.S. GAAP”), as indicated below. Users of financial information produced for interim periods in 2018 are encouraged to read this Quarterly Report on Form 10-Q in conjunction with our consolidated financial statements and notes thereto filed with the Securities and Exchange Commission (“SEC”) in our 2017 Annual Report on Form 10-K. In the past, Superior has used a 4-4-5 convention for our fiscal quarters, which are thirteen-week periods (referred to as quarters) ending on the last Sunday of each calendar quarter. Therefore, the first quarter in 2017 started on December 26, 2016 and ended on March 26, 2017. Our European operations have historically reported on a calendar year basis, and, beginning on December 31, 2017, both our North American and European operations were reported on a calendar fiscal year with each month ending on the last day of the calendar month. Thus, the first quarter of 2018 ended on March 31, 2018. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the SEC’s requirements for quarterly reports on Form 10-Q and U.S. GAAP and, in our opinion, contain all adjustments, of a normal and recurring nature, which are necessary for a fair statement of (i) the condensed consolidated statements of operations for the three month periods ended March 31, 2018 and March 26, 2017, (ii) the condensed consolidated statements of comprehensive income for the three month periods ended March 31, 2018 and March 26, 2017, (iii) the condensed consolidated balance sheets at March 31, 2018 and December 31, 2017, (iv) the condensed consolidated statements of cash flows for the three month periods ended March 31, 2018 and March 26, 2017, and (v) the condensed consolidated statement of shareholders’ equity for the three month period ended March 31, 2018. However, the accompanying unaudited condensed consolidated financial statements do not include all information and notes required by U.S. GAAP. The condensed consolidated balance sheet as of December 31, 2017, included in this report was derived from our 2017 audited financial statements, but does not include all disclosures required by U.S. GAAP. Interim financial reporting standards require us to make estimates that are based on assumptions regarding the outcome of future events and circumstances not known at that time, including the use of estimated effective tax rates. Inevitably, some assumptions will not materialize, unanticipated events or circumstances may occur which vary from those estimates and such variations may significantly affect our future results. Additionally, interim results may not be indicative of our results for future interim periods or our annual results.
Use of Estimates	Interim financial reporting standards require us to make estimates that are based on assumptions regarding the outcome of future events and circumstances not known at that time, including the use of estimated effective tax rates. Inevitably, some assumptions will not materialize, unanticipated events or circumstances may occur which vary from those estimates and such variations may significantly affect our future results. Additionally, interim results may not be indicative of our results for future interim periods or our annual results.
New Accounting Standards	New Accounting Standards Adoption of New Accounting Standards ASU 2014-09, Topic 606,“Revenue – Revenue from Contracts with Customers” (including all related amendments). On January 1, 2018, we adopted “Revenue from Contracts with Customers” and all the related amendments (the “new revenue standard”) to all contracts using the modified retrospective method. Implementation of the standard does not have a material effect on our financial position or results of operations as the company’s method for recognizing revenue under the new standard does not vary significantly from revenue recognition practices under the prior standard. ASU 2017-12 Improvements to Hedge Accounting Activities.” On January 1, 2018, we adopted the “Targeted Improvements to Accounting for Hedging Activities.” This standard removes the requirement to recognize hedge ineffectiveness in income prior to settlement, allows documentation of hedge effectiveness at inception to be completed by quarter-end, allows qualitative rather than quantitative assessment of effectiveness (subsequent to initial quantitative assessment), allows critical terms match for cash flow hedges of a group of forecasted transactions (if derivatives mature within the same month as transactions), permits use of the “back up” long haul method for hedges initially designated using the short cut method and permits cash flow hedging of a component of purchases and sales of non-financial assets (i.e., commodity price excluding transportation) resulting in higher hedge effectiveness. The standard also permits fair value hedging of the benchmark interest rate component of interest rate risk as well as partial term hedging, permits cash flow hedging of interest rate risk for a contractually specified rate rather than a benchmark rate and permits exclusion of cross currency basis spread in determining effectiveness. The provisions of this standard apply prospectively so there is no cumulative balance sheet adjustment or restatement associated with adoption of this standard. The principal change in accounting for hedges under this standard is that hedge ineffectiveness (for qualifying hedges subject to hedge accounting) will be recognized in other comprehensive income (rather than earnings) until the hedged item is recognized in earnings, at which point accumulated gains or losses will be recognized in earnings and classified with the underlying hedged expense. In the past, we had applied hedge accounting to our foreign currency hedging activity. The company has elected to apply hedge accounting to aluminum swaps used to hedge the commodity price component of its aluminum purchases for its aftermarket business effective March 1, 2018. ASU 2016-16, “Classification of Certain Cash Receipts and Cash Payments.” We adopted this standard as of January 1, 2018. The objective of the ASU is to address the diversity in practice in the presentation of certain cash receipts and cash payments in the statement of cash flows. We do not expect this standard to have a material effect on our financial condition or results of operations. ASU 2017-07, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.” In March 2017, the FASB issued this standard to improve the reporting of net benefit cost in the financial statements. We have adopted this standard as of January 1, 2018. Due to the immateriality of our pension and postretirement costs, this standard does not have a material effect on our financial condition or results of operations. Accordingly, no restatement of previously issued financial statements is necessary and the provisions of this standard will be applied prospectively. ASU 2017-11, “(Part I) Accounting for Certain Financial Instruments with Down Round Features, (Part II) Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception.” The objective of this standard is to reduce the complexity in accounting for certain financial instruments with down round features. When determining whether certain financial instruments should be classified as debt or equity instruments, a down round feature would no longer preclude equity classification when assessing whether the instrument is indexed to an entity’s own stock. As a result, a freestanding equity-linked financial instrument (or embedded conversion option) no longer would be accounted for as a derivative liability at fair value as a result of the existence of a down round feature. The company has no relevant transactions at the present time. As a result, this standard does not have a material effect on our financial condition or results of operations. ASU 2017-01, “Clarifying the Definition of a Business.” We have adopted this standard as of January 1, 2018. The objective of the ASU is to add guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. This standard does not have a material effect on our financial condition or results of operations since we have no imminent acquisitions. ASU 2016-18, “Restricted Cash.” The objective of the ASU is to address the diversity in practice that exists in the classification and presentation of changes in restricted cash on the statement of cash flows. This standard does not have a material effect on our financial condition or results of operations since we have no restricted cash balances at the present time. ASU 2016-16, “Intra-Entity Transfers of Assets Other than Inventory.” The objective of the ASU is to improve the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. This standard does not have a material effect on our financial condition or results of operations since we have no significant intra-entity transfers other than inventory. Accounting Standards Issued But Not Yet Adopted ASU 2016-02, “Leases.” In February of 2016, the FASB issued “Leases”. ASU 2016-02 requires an entity to recognize right-of-use assets and lease liabilities on its balance sheet and disclose key information about leasing arrangements. ASU 2016-02 offers specific accounting guidance for a lessee, a lessor and sale and leaseback transactions. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. For public companies, ASU 2016-02 is effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period, and requires modified retrospective adoption, with early adoption permitted. We are evaluating the impact this guidance will have on our financial position and statement of operations. ASU 2017-04, “Simplifying the Test for Goodwill Impairment.” In January 2017, the FASB issued an ASU entitled “Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” The objective of the ASU is to simplify how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. This ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted. We are evaluating the impact this guidance will have on our financial position and statement of operations. ASU 2018-02, “Income Statement — Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” In January 2018, the FASB issued ASU 2018-02, “Income Statement — Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income,” which gives entities the option to reclassify to retained earnings the tax effects resulting from the Tax Cuts and Jobs Act (“the Act”) related to items in accumulated other comprehensive income (AOCI) that the FASB refers to as having been stranded in AOCI. The new guidance may be applied retrospectively to each period in which the effect of the Act is recognized in the period of adoption. The Company must adopt this guidance for fiscal years beginning after 15 December 2018 and interim periods within those fiscal years. Early adoption is permitted for periods for which financial statements have not yet been issued or made available for issuance, including the period the Act was enacted. The guidance, when adopted, will require new disclosures regarding a company’s accounting policy for releasing the tax effects in AOCI and permit the company the option to reclassify to retained earnings the tax effects resulting from the Act that are stranded in AOCI. We are evaluating the impact this guidance will have on our financial position and statement of operations.
Fair Value Measurements	The company applies fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis, while other assets and liabilities are measured at fair value on a nonrecurring basis, such as when we have an asset impairment. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: Level 1 – Quoted prices in active markets for identical assets or liabilities. Level 2 – Observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 – Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability.
Derivatives, Methods of Accounting, Hedging Derivatives	Derivative Instruments and Hedging Activities We use derivatives to partially offset our business exposure to foreign currency risk. We may enter into forward contracts, option contracts, swaps, collars or other derivative instruments to offset some of the risk on expected future cash flows and on certain existing assets and liabilities. However, we may choose not to hedge certain exposures for a variety of reasons including, but not limited to, accounting considerations and the prohibitive economic cost of hedging particular exposures. There can be no assurance the hedges will offset more than a portion of the financial impact resulting from movements in foreign currency exchange rates. To help protect gross margins from fluctuations in foreign currency exchange rates, certain of our subsidiaries, whose functional currency is the U.S. dollar or the Euro, hedge a portion of forecasted foreign currency costs denominated in the Mexican Peso and Polish Zloty, respectively. We may hedge portions of our forecasted foreign currency exposure up to 48 months. We record all derivatives in the condensed consolidated balance sheets at fair value. Our accounting treatment for these instruments is based on the hedge designation. The cash flow hedges that are designated as hedging instruments are recorded in Accumulated Other Comprehensive Income (“AOCI”) until the hedged item is recognized in earnings, at which point accumulated gains or losses will be recognized in earnings and classified with the underlying hedged expense. Derivatives that are not designated as hedging instruments are adjusted to fair value through earnings in the financial statement line item to which the derivative relates. At March 31, 2018, the company held derivatives that were designated as hedging instruments as well as derivatives that did not qualify for designation as hedging instruments as discussed below. Deferred gains and losses associated with cash flow hedges of foreign currency costs are recognized as a component of cost of sales in the same period as the related cost is recognized. Our foreign currency transactions hedged with cash flow hedges as of March 31, 2018, are expected to occur within 1 month to 48 months. Derivative instruments designated as cash flow hedges must be de-designated as hedges when it is probable the forecasted hedged transaction will not occur in the initially identified time period or within a subsequent two-month time period. Deferred gains and losses in AOCI associated with such derivative instruments are reclassified immediately into other expense. Any subsequent changes in fair value of such derivative instruments are reflected in other expense unless they are re-designated as hedges of other transactions. Currency option derivative contracts not designated for hedge accounting consist principally of certain option contracts to purchase the Polish Zloty and the Euro and a Euro-U.S. dollar cross currency swap. See Note 3, “Acquisition.”
Derivatives, Methods of Accounting, Derivatives Not Designated or Qualifying as Hedges	Derivatives that are not designated as hedging instruments are adjusted to fair value through earnings in the financial statement line item to which the derivative relates.
Short-Term Investments	Certificates of deposit and fixed deposits whose original maturity is greater than three months and is one year or less are classified as short-term investments and certificates of deposit and fixed deposits whose maturity is greater than one year at the balance sheet date are classified as non-current assets in our condensed consolidated balance sheets. The purchase of any certificates of deposit or fixed deposits that are classified as short-term investments or non-current assets appear in the investing section of our condensed consolidated statements of cash flows.
Earnings Per Share	In accordance with U.S. GAAP, basic earnings per share is computed by dividing net income (loss) attributable to Superior, less preferred dividends, by the weighted average number of common shares outstanding. For purposes of calculating diluted earnings per share, net income (loss) attributable to Superior is divided by the total of the weighted average shares outstanding plus the dilutive effect of our redeemable preferred stock, outstanding stock options and time and performance based restricted stock units under the treasury stock method, which includes consideration of stock-based compensation required by U.S. GAAP.