Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2015
Accounting Policies [Abstract]
Nature of Business, Policy [Policy Text Block]	Nature of Business The Company is a leading U.S. metals service center specializing in the processing and distribution of large volumes of carbon, coated, aluminum and stainless steel, flat-rolled coil, sheet and plate products and tubular and pipe products from facilities throughout the United States. The Company now operates in three reportable segments; carbon flat products, specialty metals flat products, and tubular and pipe products. The carbon flat products segment and the specialty metals flat products segments are at times consolidated and referred to as the flat products segments. The flat products segments’ assets and resources are shared by the carbon and specialty metals segments and both segments’ products are stored in the shared facilities and processed on the shared equipment. Due to the shared assets and resources, certain of the flat products segment expenses are allocated between the carbon flat products segment and the specialty metals flat products segment based upon an established allocation methodology. 2014 financial information has been recast to reflect the new segment reporting structure. Due to system limitations, 2013 financial information is presented for the consolidated flat products segments. Through its carbon flat products segment, the Company sells and distributes large volumes of processed carbon and coated flat-rolled sheet, coil and plate products, and fabricated parts. Through its specialty metals flat products segment, the Company sells and distributes processed aluminum and stainless flat-rolled sheet and coil products, flat bar products and fabricated parts. Through its tubular and pipe products segment, the Company distributes metal tubing, pipe, bar, valve and fittings and fabricates pressure parts supplied to various industrial markets.
Consolidation, Policy [Policy Text Block]	Principles of Consolidation and Basis of presentation The accompanying consolidated financial statements include the accounts of Olympic Steel, Inc. and its wholly-owned subsidiaries (collectively, the Company or Olympic), after elimination of intercompany accounts and transactions.
Use of Estimates, Policy [Policy Text Block]	Accounting Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Concentration Risks The Company is a major customer of flat-rolled coil and plate and tubular and pipe steel for many of its principal suppliers, but is not dependent on any one supplier. The Company purchased approximately 51%, 43% and 42% of its total steel requirements from its three largest suppliers in 2015, 2014 and 2013, respectively. The Company has a diversified customer and geographic base, which reduces the inherent risk and cyclicality of its business. The concentration of net sales to the Company’s top 20 customers approximated 31%, 29% and 30% of consolidated net sales in 2015, 2014 and 2013, respectively. In addition, the Company’s largest customer accounted for approximately 6%, 6% and 5% of consolidated net sales in 2015, 2014 and 2013, respectively. Sales to industrial machinery and equipment manufacturers and their fabricators accounted for 49%, 51% and 50% of consolidated net sales in 2015, 2014 and 2013, respectively.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents Cash equivalents consist of short-term highly liquid investments, with a three month or less maturity, which are readily convertible into cash.
Fair Value Measurement, Policy [Policy Text Block]	Fair Market Value Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the liability in an orderly transaction between market participants on the measurement date. Valuation techniques must maximize the use of observable inputs and minimize the use of unobservable inputs. To measure fair value, the Company applies a fair value hierarchy that is based on three levels of inputs, of which the first two are considered observable and the last unobservable, as follows: Level 1 – Quoted prices in active markets for identical assets or liabilities. Level 2 – Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices that are not active; 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 – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Financial instruments, such as cash and cash equivalents, accounts receivable, accounts payable and the credit facility revolver, are stated at their carrying value, which is a reasonable estimate of fair value. The fair value of marketable securities is based on quoted market prices.
Trade and Other Accounts Receivable, Policy [Policy Text Block]	Accounts Receivable The Company’s allowance for doubtful accounts is maintained at a level considered appropriate based on historical experience and specific customer collection issues that the Company has identified. Estimations are based upon a calculated percentage of accounts receivable, which remains fairly level from year to year, and judgments about the probable effects of economic conditions on certain customers, which can fluctuate significantly from year to year. The Company cannot guarantee that the rate of future credit losses will be similar to past experience.
Inventory, Policy [Policy Text Block]	Inventories Inventories are stated at the lower of cost or market and include the costs of purchased metals, inbound freight, external processing and applicable labor and overhead costs. Costs of our carbon and specialty metals flat products segments’ inventories, including flat-rolled sheet, coil and plate products are determined using the specific identification method. Certain of the Company’s tubular and pipe products inventory is stated under the last-in, first-out (LIFO) method. At December 31, 2015 and December 31, 2014, approximately $42.7 million, or 20.7% of consolidated inventory, and $46.6 million, or 15.0% of consolidated inventory, respectively, was reported under the LIFO method of accounting. The cost of the remainder of tubular and pipe product segment’s inventory is determined using a weighted average rolling first-in, first-out (FIFO) method. On the Consolidated Statements of Comprehensive Income, “Cost of materials sold (exclusive of items shown separately below)” consists of the cost of purchased metals, inbound and internal transfer freight, external processing costs, and LIFO income or expense.
Property, Plant and Equipment, Policy [Policy Text Block]	Property and Equipment, and Depreciation Property and equipment are stated at cost. Depreciation is provided using the straight-line method over the estimated useful lives of the assets ranging from two to 30 years. The Company capitalizes the costs of obtaining or developing internal-use software, including directly related payroll costs. The Company amortizes those costs over five years, beginning when the software is ready for its intended use.
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]	Goodwill and Other Intangible Assets Goodwill represents the excess of the purchase price paid over the fair value of the net assets acquired. The Company performs an annual impairment test of goodwill for the specialty metals flat products and tubular and pipe products segments and indefinite-lived intangible assets for the tubular and pipe products segment in the fourth quarter, or more frequently if changes in circumstances or the occurrence of events indicate potential impairment. Events or changes in circumstances that could trigger an impairment review include significant nonperformance relative to the expected historical or projected future operating results, significant changes in the manner of the use of the acquired assets or the strategy for the overall business or significant negative industry or economic trends. Management uses judgment to determine whether to use a qualitative analysis or a quantitative fair value measurement for each of the Company’s reporting units that carry goodwill. If a quantitative fair value measurement is used, the fair value of each indefinite-lived intangible asset is compared to its carrying value and an impairment charge is recorded if the carrying value exceeds the fair value. Goodwill is tested by comparing the fair value of each reporting unit with its carrying value. If the carrying value of the reporting unit exceeds its fair value, the implied value of goodwill is compared to its carrying value and impairment is recognized to the extent that the carrying value exceeds the implied fair value. The Company estimates the fair value of goodwill and other indefinite-lived intangible assets using a discounted cash flow methodology, an income approach, and a publicly traded companies guideline method, a market approach. Management’s assumptions used for the calculations are based on historical results, projected financial information and recent economic events. Actual results could differ from these estimates under different assumptions or conditions which could adversely affect the reported value of goodwill. During 2015, the metals industry experienced a significant decline in the price of metals as a result of the strengthened U.S. dollar, a historically high level of imported materials arriving in the United States, low raw material costs to produce metals, and an oversupply of metals. As a result, the Company determined that a triggering event occurred in the Company’s tubular and pipe products segment during the second quarter of 2015. The challenging market conditions negatively impacted the segment’s financial performance and the decrease of the Company’s market capitalization led the Company to perform the two-step quantitative impairment test by comparing the fair value of the tubular and pipe products segment with its carrying value. The Company engaged an independent third-party valuation expert to assist with the completion of the goodwill and indefinitely lived intangible asset impairment testing. The asset impairment testing determined that the carrying value of the operations was in excess of the fair value and indefinitely lived intangible asset and goodwill impairments were identified. The Company concluded that the indefinitely lived intangible asset, Trade name, was partially impaired and the impairment in the amount of $8.0 million was recorded in the second quarter of 2015. Based on the second step of the impairment test, the Company concluded that the implied fair value of goodwill for the tubular and pipe products segment was less than its carrying value and a full goodwill impairment of $16.5 million was recorded at June 30, 2015. The metals industry continued to experience declining metals prices in the second half of 2015 as well as declining nickel prices. As a result, the Company concluded during its annual goodwill impairment analysis during the fourth quarter of 2015 that the $500 thousand of goodwill related to the specialty metals flat products segment was impaired as the implied fair value of goodwill for specialty metals flat products segment was less than its carrying value. At December 31, 2015, all of the Company’s goodwill had been fully impaired.
Income Tax, Policy [Policy Text Block]	Income Taxes The Company, on its consolidated balance sheets, records as an offset to the estimated effect of temporary differences between the tax basis of assets and liabilities and the reported amounts in its consolidated balance sheets, the tax effect of operating loss and tax credit carryforwards. If the Company determines that it will not be able to fully realize a deferred tax asset, it will record a valuation allowance to reduce such deferred tax asset to its realizable value. The Company recognizes interest accrued related to unrecognized tax benefits in income tax expense. Penalties, if incurred, would be recognized as a component of administrative and general expense.
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition For both direct and toll shipments, revenue is recognized when title and risk of loss is transferred, which generally occurs upon delivery to our customers. Given the proximity of the Company’s customers to its facilities, substantially all of the Company’s sales are shipped and received within one day. Sales returns and allowances are treated as reductions to sales and are provided for based on historical experience and current estimates and are immaterial to the consolidated financial statements. The engineered products produced by Chicago Tube and Iron Company (CTI) typically take several months to produce due to their size and complexity. Substantially all projects are completed within six months. The Company may request advance payments from customers during the production of these products. These payments are included in current short-term liabilities on the Company’s Consolidated Balance Sheet. Due to their short-term nature, the Company uses the units of delivery method to account for these contracts. Revenue for the contracts is recognized when the product is shipped and title of the product transfers to the customers. Revenues for these engineered products accounted for approximately 1.8%, 1.7% and 1.9% of our net sales during 2015, 2014 and 2013, respectively.
Shipping and Handling Cost, Policy [Policy Text Block]	Shipping and Handling Fees and Costs Amounts charged to customers for shipping and other transportation services are included in net sales. The distribution expense line on the accompanying Consolidated Statements of Comprehensive Income is entirely comprised of all shipping and other transportation costs incurred by the Company in shipping goods to its customers.
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Recoverability of Long-lived Assets The Company evaluates the recoverability of long-lived assets and the related estimated remaining lives whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Events or changes in circumstances that could trigger an impairment review include significant underperformance relative to the expected historical or projected future operating results, significant changes in the manner of the use of the acquired assets or the strategy for the overall business or significant negative industry or economic trends. The Company records an impairment or change in useful life whenever events or changes in circumstances indicate that the carrying amount may not be recoverable or the useful life has changed. Due to the impairment of the tubular and pipe products and specialty metals segments’ goodwill, a triggering event occurred for the long-lived assets of the Company. We performed an undiscounted cash flow analysis that demonstrated there were no indicators of impairment of the long-lived assets of the Company. Additionally, the indefinite lived intangible asset was tested for impairment due to the triggering event. This test identified an impairment to the Company’s intangible assets of $8.0 million, which was recorded in the second quarter of 2015. Based on the Company’s analysis in the fourth quarter of 2015, there were no further impairments of the Company’s long-lived assets in 2015.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Stock-Based Compensation The Company records compensation expense for stock options issued to employees and directors. For additional information, see Note 10, Equity Plans.
New Accounting Pronouncements, Policy [Policy Text Block]	Impact of Recently Issued Accounting Pronouncements In November, 2015, Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2015-17, “Balance Sheet Classification of Deferred Taxes.” This ASU is part of the FASB’s Simplification Initiative and has been issued to reduce complexity in the presentation of deferred taxes. This new guidance eliminates the requirement for entities that present a classified statement of financial position to classify deferred tax assets and liabilities as current and noncurrent, and instead require that they classify all deferred tax assets and liabilities as noncurrent. As a result, each jurisdiction will now only have one net noncurrent deferred tax asset or liability. However, the guidance does not change the existing requirement that only permits offsetting within a jurisdiction. Companies are still prohibited from offsetting deferred tax liabilities from one jurisdiction against deferred tax assets of another jurisdiction. This ASU is effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years, with early adoption permitted. The Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements. The guidance may be applied either prospectively, for all deferred tax assets and liabilities, or retrospectively (i.e., by reclassifying the comparative balance sheet). If applied prospectively, entities are required to include a statement that prior periods were not retrospectively adjusted. If applied retrospectively, entities are also required to include quantitative information about the effects of the change on prior periods. The adoption of this ASU is not expected to materially impact the Company’s consolidated financial statements. In April 2015, FASB issued ASU No. 2015-03, “Simplifying the Presentation of Debt Issuance Costs.” This ASU is part of the FASB’s Simplification Initiative and has been issued to reduce the complexity in the presentation of debt issuance costs. This new guidance requires companies to present debt issuance costs the same way they currently present debt discounts, as a direct deduction from the carrying value of that debt liability. The guidance is limited to simplifying the presentation of debt issuance costs and does not impact the recognition and measurement guidance for debt issuance costs. This ASU is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years, with early adoption permitted. The amendments of ASU No. 2015-03 must be applied retrospectively, where the balance sheet of each presented individual period is adjusted to indicate the period-specific impact of using the new guidance. The FASB considered that because both debt issuance costs and debt discounts are amortized using the effective interest method, there would be no effect on the income statement upon adoption of the amendments. The adoption of this guidance on January 1, 2016 did not have a material impact on the Company’s consolidated financial statements. In August 2014, the FASB issued an amendment to the accounting guidance on disclosure of uncertainties about an entity’s ability to continue as a going concern. This guidance requires management to assess the Company’s ability to continue as a going concern and to provide disclosures under certain circumstances. This guidance is effective for annual reporting periods ending after December 15, 2016 and interim reporting periods thereafter. Early adoption is permitted. The Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers.” This ASU is a joint project initiated by the FASB and the International Accounting Standards Board to clarify the principles for recognizing revenue and to develop a common revenue standard for U.S. generally accepted accounting principles and International Financial Reporting Standards that will: remove inconsistencies and weaknesses in revenue requirements; provide a more robust framework for addressing revenue issues; improve comparability of revenue recognition practices across entities, industries, jurisdictions and capital markets; provide more useful information to users of financial statements through improved disclosure requirements; and simplify the preparation of financial statements by reducing the number of requirements to which an entity must refer. As originally proposed, the guidance is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The Company is in the process of determining the method of adoption and assessing the impact of this ASU on its consolidated financial statements, and interim periods within those fiscal years, with early adoption permitted. In August 2015, the FASB issued ASU No. 2015-14, “Revenue from contracts with customers.” This ASU deferred the effective date of ASU No. 2014-09 by one year.