Nature of Operations and Presentation of Condensed Consolidated Financial Statements (Policies)	9 Months Ended
Sep. 30, 2020
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations Superior Industries International, Inc.’s (referred herein as the “Company,” “Superior,” or “we” and “our”) principal business is the design and manufacture of aluminum wheels for sale to original equipment manufacturers (OEMs) in North America and Europe and aftermarket distributors in Europe. We employ approximately 7,500 employees, operating in eight manufacturing facilities in North America and Europe with a combined annual manufacturing capacity of approximately 20 million wheels. We are one of the largest suppliers to global OEMs and we believe we are the #1 European aluminum wheel aftermarket manufacturer and supplier. Our OEM aluminum wheels accounted for approximately 92 percent of our sales in the first nine months of 2020 and are primarily sold for factory installation on vehicle models manufactured by BMW (including Mini), Daimler AG Company (Mercedes-Benz, AMG, Smart), FCA, Ford, GM, Honda, Jaguar-Land Rover, Mazda, Mitsubishi, Nissan, PSA, Renault, Subaru, Suzuki, Toyota, VW Group (Volkswagen, Audi, SEAT, Skoda, Porsche, Bentley) and Volvo. We also sell aluminum wheels to the European aftermarket under the brands ATS, RIAL, ALUTEC and ANZIO. North America and Europe represent the principal markets for our products, but we have a global presence and diversified customer base consisting of North American, European and Asian OEMs. We have determined that our North American and European operations should be treated as separate reportable segments as further described in Note 5, “Business Segments.”
Presentation of Condensed Consolidated Financial Statements	Presentation of Condensed Consolidated Financial Statements The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the Security and Exchange Commission’s (“SEC’s”) requirements for quarterly reports on Form 10-Q and U.S. Generally Accepted Accounting Principles (“GAAP”) and, in our opinion, contain all adjustments, of a normal and recurring nature, which are necessary for fair presentation of (i) the condensed consolidated statements of income (loss) for the three and nine-month periods ended September 30, 2020 and September 30, 2019, (ii) the condensed consolidated statements of comprehensive income (loss) for the three and nine-month periods ended September 30, 2020 and September 30, 2019, (iii) the condensed consolidated balance sheets at September 30, 2020 and December 31, 2019, (iv) the condensed consolidated statements of cash flows for the nine-month periods ended September 30, 2020 and September 30, 2019, and (v) the condensed consolidated statements of shareholders’ equity (deficit) for the three and nine-month periods ended September 30, 2020 and September 30, 2019. This Quarterly Report on Form 10-Q should be read in conjunction with our consolidated financial statements and notes thereto filed with the SEC in our 2019 Annual Report on Form 10-K. 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. Certain prior year amounts have been reclassified to conform with the current year presentation.
Cash Paid for Interest and Taxes and Non-Cash Investing Activities	Cash Paid for Interest and Taxes and Non-Cash Investing Activities Cash paid for interest was $27.1 million and $28.2 million for the nine months ended September 30, 2020 and September 30, 2019, respectively. Net cash income taxes paid was $7.6 million and $6.5 million for the nine months ended September 30, 2020 and September 30, 2019, respectively. As of September 30, 2020 and September 30, 2019, $0.2 million and $15.8 million, respectively, of equipment had been purchased but not yet paid and was included in accounts payable in our condensed consolidated balance sheets.
New Accounting Standards	New Accounting Standards Accounting Standards Update (“ASU”) 2018-13, “Fair Value Measurement.” Effective January 1, 2020, the Company adopted ASU 2018-13 which allows companies to remove, modify and add certain disclosures related to fair value measurements. The adoption of this standard did not have a significant impact on the Company’s condensed consolidated financial statement disclosures. Accounting Standards Issued but Not Yet Adopted ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” In June 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-13, "Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments", which requires entities to use a new impairment model based on current expected credit losses (“CECL”) rather than incurred losses. Under CECL, estimated credit losses would incorporate relevant information about past events, current conditions and reasonable and supportable forecasts and any expected credit losses would be recognized at the time of sale. As a smaller reporting company (as defined under SEC regulations), the Company is not required to adopt the standard until fiscal years beginning after December 31, 2022. We are evaluating the impact this standard will have on our financial statements and disclosures. ASU 2018-14, “Compensation - Retirement Benefits - Defined Benefit Plans.” In August 2018, the FASB issued an ASU entitled “Compensation - Retirement Benefits - Defined Benefit Plans - General Subtopic 715-20 - Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans” (ASU 2018-14), which is designed to improve the effectiveness of disclosures by removing and adding disclosures related to defined benefit plans. ASU 2018-14 is effective for fiscal years ending after December 15, 2020. We are evaluating the impact this new standard will have on our financial statement disclosures. ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” In March 2020, the FASB issued ASU 2020-04 entitled “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting,” which provides temporary optional guidance to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. The relief provided by this guidance is elective and applies to all entities, subject to meeting certain criteria, that have contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate (“LIBOR”) or another reference rate expected to be discontinued because of reference rate reform initiatives being undertaken in an effort to identify alternative reference rates that are more observable or transaction based and less susceptible to manipulation. The optional amendments of this guidance are effective for all entities upon adoption. We are currently assessing the impact of this new standard on our financial statements and disclosures.
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 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. The carrying amounts for cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximate their fair values due to the short period of time until maturity.
Derivatives, Methods of Accounting, Hedging Derivatives	Derivative Instruments and Hedging Activities We use derivatives to partially offset our exposure to foreign currency, interest rate, aluminum and other commodity price 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, interest rates, and aluminum or other commodity prices. 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 their 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. Gains or losses on derivatives that are designated as hedging instruments are recorded in accumulated other comprehensive income (loss) (“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 transaction. 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. The Company has derivatives that are designated as hedging instruments as well as derivatives that do not qualify for designation as hedging instruments.
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.

Nature of Operations and Presentation of Condensed Consolidated Financial Statements (Policies)

9 Months Ended

Sep. 30, 2020

Superior Industries International, Inc.’s (referred herein as the “Company,” “Superior,” or “we” and “our”) principal business is the design and manufacture of aluminum wheels for sale to original equipment manufacturers (OEMs) in North America and Europe and aftermarket distributors in Europe. We employ approximately 7,500 employees, operating in eight manufacturing facilities in North America and Europe with a combined annual manufacturing capacity of approximately 20 million wheels. We are one of the largest suppliers to global OEMs and we believe we are the #1 European aluminum wheel aftermarket manufacturer and supplier. Our OEM aluminum wheels accounted for approximately 92 percent of our sales in the first nine months of 2020 and are primarily sold for factory installation on vehicle models manufactured by BMW (including Mini), Daimler AG Company (Mercedes-Benz, AMG, Smart), FCA, Ford, GM, Honda, Jaguar-Land Rover, Mazda, Mitsubishi, Nissan, PSA, Renault, Subaru, Suzuki, Toyota, VW Group (Volkswagen, Audi, SEAT, Skoda, Porsche, Bentley) and Volvo. We also sell aluminum wheels to the European aftermarket under the brands ATS, RIAL, ALUTEC and ANZIO. North America and Europe represent the principal markets for our products, but we have a global presence and diversified customer base consisting of North American, European and Asian OEMs. We have determined that our North American and European operations should be treated as separate reportable segments as further described in Note 5, “Business Segments.”

Presentation of Condensed Consolidated Financial Statements

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the Security and Exchange Commission’s (“SEC’s”) requirements for quarterly reports on Form 10-Q and U.S. Generally Accepted Accounting Principles (“GAAP”) and, in our opinion, contain all adjustments, of a normal and recurring nature, which are necessary for fair presentation of (i) the condensed consolidated statements of income (loss) for the three and nine-month periods ended September 30, 2020 and September 30, 2019, (ii) the condensed consolidated statements of comprehensive income (loss) for the three and nine-month periods ended September 30, 2020 and September 30, 2019, (iii) the condensed consolidated balance sheets at September 30, 2020 and December 31, 2019, (iv) the condensed consolidated statements of cash flows for the nine-month periods ended September 30, 2020 and September 30, 2019, and (v) the condensed consolidated statements of shareholders’ equity (deficit) for the three and nine-month periods ended September 30, 2020 and September 30, 2019. This Quarterly Report on Form 10-Q should be read in conjunction with our consolidated financial statements and notes thereto filed with the SEC in our 2019 Annual Report on Form 10-K.

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.

Certain prior year amounts have been reclassified to conform with the current year presentation.

Cash Paid for Interest and Taxes and Non-Cash Investing Activities

Cash paid for interest was $27.1 million and $28.2 million for the nine months ended September 30, 2020 and September 30, 2019, respectively. Net cash income taxes paid was $7.6 million and $6.5 million for the nine months ended September 30, 2020 and September 30, 2019, respectively. As of September 30, 2020 and September 30, 2019, $0.2 million and $15.8 million, respectively, of equipment had been purchased but not yet paid and was included in accounts payable in our condensed consolidated balance sheets.

New Accounting Standards

Accounting Standards Update (“ASU”) 2018-13, “Fair Value Measurement.” Effective January 1, 2020, the Company adopted ASU 2018-13 which allows companies to remove, modify and add certain disclosures related to fair value measurements. The adoption of this standard did not have a significant impact on the Company’s condensed consolidated financial statement disclosures.

Accounting Standards Issued but Not Yet Adopted

ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” In June 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-13, "Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments", which requires entities to use a new impairment model based on current expected credit losses (“CECL”) rather than incurred losses. Under CECL, estimated credit losses would incorporate relevant information about past events, current conditions and reasonable and supportable forecasts and any expected credit losses would be recognized at the time of sale. As a smaller reporting company (as defined under SEC regulations), the Company is not required to adopt the standard until fiscal years beginning after December 31, 2022. We are evaluating the impact this standard will have on our financial statements and disclosures.

ASU 2018-14, “Compensation - Retirement Benefits - Defined Benefit Plans.” In August 2018, the FASB issued an ASU entitled “Compensation - Retirement Benefits - Defined Benefit Plans - General Subtopic 715-20 - Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans” (ASU 2018-14), which is designed to improve the effectiveness of disclosures by removing and adding disclosures related to defined benefit plans. ASU 2018-14 is effective for fiscal years ending after December 15, 2020. We are evaluating the impact this new standard will have on our financial statement disclosures.

ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” In March 2020, the FASB issued ASU 2020-04 entitled “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting,” which provides temporary optional guidance to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. The relief provided by this guidance is elective and applies to all entities, subject to meeting certain criteria, that have contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate (“LIBOR”) or another reference rate expected to be discontinued because of reference rate reform initiatives being undertaken in an effort to identify alternative reference rates that are more observable or transaction based and less susceptible to manipulation. The optional amendments of this guidance are effective for all entities upon adoption. We are currently assessing the impact of this new standard on our financial statements and disclosures.

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 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.

The carrying amounts for cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximate their fair values due to the short period of time until maturity.

Derivatives, Methods of Accounting, Hedging Derivatives

Derivative Instruments and Hedging Activities

We use derivatives to partially offset our exposure to foreign currency, interest rate, aluminum and other commodity price 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, interest rates, and aluminum or other commodity prices.

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 their 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. Gains or losses on derivatives that are designated as hedging instruments are recorded in accumulated other comprehensive income (loss) (“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 transaction. 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. The Company has derivatives that are designated as hedging instruments as well as derivatives that do not qualify for designation as hedging instruments.

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.