Summary of Accounting Policies (Policies)	12 Months Ended
Summary of Accounting Policies (Policies)	Dec. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of HNH and its subsidiaries. All material intercompany transactions and balances have been eliminated.
Discontinued Operations	Discontinued Operations The results of operations for businesses that have been disposed of or classified as held-for-sale are segregated from the results of the Company's continuing operations and classified as discontinued operations for each period presented in the Company's consolidated statements of operations. Similarly, the assets and liabilities of such businesses are reclassified from continuing operations and presented as discontinued operations for each period presented on the Company's consolidated balance sheets.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP") requires the Company to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. On an on-going basis, the Company evaluates its estimates, including those related to bad debts, inventories, long-lived assets, intangibles, accrued liabilities, income taxes, pension and other post-retirement benefit obligations, and contingencies and litigation. Estimates are based on historical experience, expected future cash flows and various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates.
Revenue Recognition	Revenue Recognition Revenues are recognized when title and risk of loss has passed to the customer. This condition is normally met when product has been shipped or the service performed. An allowance is provided for estimated returns and discounts based on experience. Cash received by the Company from customers prior to shipment of goods, or otherwise not yet earned, is recorded as deferred revenue. Rental revenues are derived from the rental of certain equipment to the food industry where customers prepay for the rental period, usually three to six month periods. For prepaid rental contracts, sales revenue is recognized on a straight-line basis over the term of the contract. Service revenues consist of repair and maintenance work performed on equipment used at mass merchants, supermarkets and restaurants. The Company experiences a certain degree of sales returns that varies over time, but is able to make a reasonable estimation of expected sales returns based upon history. The Company records all shipping and handling fees billed to customers as revenue, and related costs are charged principally to cost of goods sold when incurred. The Company has also entered into agreements with certain customers under which the Company has agreed to pay rebates to such customers. These programs are typically structured to incentivize the customers to increase their annual purchases from the Company. The rebates are usually calculated as a percentage of the purchase amount, and such percentages may increase as the customer's level of purchases rise. Rebates are recorded as a reduction of net sales in the consolidated statements of operations and are accounted for on an accrual basis. In limited circumstances, the Company is required to collect and remit sales tax on certain of its sales. The Company accounts for sales taxes on a net basis, and such sales taxes are not included in net sales in the consolidated statements of operations.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include cash on hand and on deposit and highly liquid debt instruments with original maturities of three months or less. The Company's credit risk arising from cash deposits held in U.S. banks in excess of insured amounts is reduced given that cash balances in U.S. banks are generally utilized to pay down the Company's revolving credit loans (see Note 11 - "Credit Facilities").
Trade Receivable and Allowance for Doubtful Accounts	Trade Receivables and Allowance for Doubtful Accounts The Company extends credit to customers based on its evaluation of the customer's financial condition. The Company does not typically require that any collateral be provided by its customers. The Company has established an allowance for accounts that are expected to be uncollectible in the future. This estimated allowance is based primarily on management's evaluation of the financial condition of the customer and historical experience. The Company monitors its trade receivables and charges to expense an amount equal to its estimate of expected credit losses. Accounts that are outstanding longer than contractual payment terms are considered past due. The Company considers a number of factors in determining its estimates, including the length of time its trade receivables are past due, the Company's previous loss history and the customer's current ability to pay its obligation. Trade receivable balances are charged off against the allowance when it is determined that the receivables will not be recovered, and payments subsequently received on such receivables are credited to recovery of accounts written-off. The Company does not typically charge interest on past due receivables. The Company believes that the credit risk with respect to trade receivables is limited due to the Company's credit evaluation process, the allowance for doubtful accounts that has been established and the diversified nature of its customer base.
Inventories	Inventories Inventories are generally stated at the lower of cost (determined by the first-in, first-out method or average cost method) or market. Cost is determined by the last-in, first-out ("LIFO") method for certain precious metal inventory held in the U.S., and remaining precious metal inventory is primarily carried at fair value. For precious metal inventory, no segregation among raw materials, work in process and finished products is practicable. Non-precious metal inventories are evaluated for estimated excess and obsolescence based upon assumptions about future demand and market conditions, and are adjusted accordingly. If actual market conditions are less favorable than those projected, future write-downs may be required.
Derivatives and Risks	Derivatives and Risks Precious Metal and Commodity Risk HNH's precious metal and commodity inventories are subject to market price fluctuations. HNH enters into commodity futures and forward contracts to mitigate the impact of price fluctuations on its precious and certain non-precious metal inventories that are not subject to fixed price contracts. The Company's hedging strategy is designed to protect it against normal volatility; therefore, abnormal price changes in these commodities or markets could negatively impact HNH's earnings. The Company does not enter into derivatives or other financial instruments for trading or speculative purposes. HNH accounts for these contracts as either fair value hedges or economic hedges under the guidance in Accounting Standards Codification ("ASC") 815, Derivatives and Hedging. Fair Value Hedges. The fair values of these derivatives are recognized as derivative assets and liabilities on the consolidated balance sheets. The net change in fair value of the derivative assets and liabilities, and the change in the fair value of the underlying hedged inventory, are recognized in the consolidated statements of operations, and such amounts principally offset each other due to the effectiveness of the hedges. The fair value hedges are associated primarily with the Company's precious metal inventory carried at fair value. Economic Hedges. As these derivatives are not designated as accounting hedges under ASC 815, they are accounted for as derivatives with no hedge designation. The derivatives are marked to market, and both realized and unrealized gains and losses are recorded in current period earnings in the consolidated statements of operations. The economic hedges are associated primarily with the Company's precious metal inventory valued using the LIFO method. Interest Rate Risk HNH has entered into interest rate swap agreements in the past in order to economically hedge a portion of its debt, which was subject to variable interest rates. As these derivatives were not designated as accounting hedges under U.S. GAAP, they were accounted for as derivatives with no hedge designation. The Company recorded the gains and losses both from the mark-to-market adjustments and net settlements in interest expense in the consolidated statements of operations as the hedges were intended to offset interest rate movements. Foreign Currency Exchange Rate Risk The Company is subject to the risk of price fluctuations related to anticipated revenues and operating costs, firm commitments for capital expenditures and existing assets and liabilities denominated in currencies other than the U.S. dollar. The Company has not generally used derivative instruments to manage this risk.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment is recorded at historical cost. Depreciation of property, plant and equipment is provided principally on the straight line method over the estimated useful lives of the assets, which range as follows: machinery and equipment 3 – 15 years and buildings and improvements 10 – 30 years. Interest cost is capitalized for qualifying assets during the asset's acquisition period. Maintenance and repairs are charged to expense, and renewals and betterments are capitalized. Gain or loss on dispositions is recorded in operating income.
Goodwill, Intangibles and Long-Lived Assets	Goodwill, Other Intangibles and Long-Lived Assets Goodwill represents the difference between the purchase price and the fair value of net assets acquired in a business combination. Goodwill is reviewed annually for impairment in accordance with U.S. GAAP as of the end of the fourth quarter. The Company uses judgment in assessing whether assets may have become impaired between annual impairment tests. Circumstances that could trigger an interim impairment test include, but are not limited to: the occurrence of a significant change in circumstances, such as continuing adverse business conditions or legal factors; an adverse action or assessment by a regulator; unanticipated competition; loss of key personnel; the likelihood that a reporting unit or significant portion of a reporting unit will be sold or otherwise disposed; or results of testing for recoverability of a significant asset group within a reporting unit. The testing of goodwill for impairment is performed at a level referred to as a reporting unit. Goodwill is allocated to each reporting unit based on the goodwill valued in connection with each business combination consummated within each reporting unit. Five reporting units of the Company have goodwill assigned to them. Goodwill impairment testing consists of a two-step process. Step 1 of the goodwill impairment test involves comparing the fair values of the applicable reporting units with their carrying values, including goodwill. If the carrying amount of a reporting unit exceeds the reporting unit's fair value, Step 2 of the goodwill impairment test is performed to determine the amount of impairment loss. Step 2 of the goodwill impairment test involves comparing the implied fair value of the affected reporting unit's goodwill against the carrying value of that goodwill. An entity has the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not (more than 50%) that the estimated fair value of a reporting unit is less than its carrying amount. If an entity elects to perform a qualitative assessment and determines that an impairment is more likely than not, the entity is then required to perform the two-step quantitative impairment test discussed above; otherwise no further analysis is required. An entity also may elect not to perform the qualitative assessment and, instead, proceed directly to the two-step quantitative impairment test. The ultimate outcome of the goodwill impairment review for a reporting unit should be the same whether an entity chooses to perform the qualitative assessment or proceeds directly to the two-step quantitative impairment test. The Company utilized a qualitative approach to assess its goodwill as of its most recent assessment date, except for the Performance Materials segment, for which the Company performed a Step 1 and a Step 2 process. Intangible assets with finite lives are amortized over their estimated useful lives. The Company also reviews long-lived assets for impairment whenever events, or changes in circumstances, indicate the carrying amount of such assets may not be recoverable. Long-lived assets consisting of land and buildings used in previously operating businesses are carried at the lower of cost or fair value less cost to sell and are included primarily in other non-current assets on the consolidated balance sheets. A reduction in the carrying value of such long-lived assets used in previously operating businesses is recorded as an asset impairment charge in the consolidated statements of operations.
Investment in Associated Company	Investment In Associated Company The Company accounts for its investment in ModusLink Global Solutions, Inc. ("ModusLink") using the equity method of accounting because the Company has the ability to exercise significant influence over the investee's operating and financial policies.
Stock-based Compensation	Stock-Based Compensation The Company accounts for stock options and restricted stock granted to employees, directors and service providers as compensation expense, which is recognized in exchange for the services received. The compensation expense is based on the fair value of the equity instruments on the grant-date and is recognized as an expense over the service period of the recipients.
Income Taxes	Income Taxes Income taxes currently payable or tax refunds receivable are recorded on a net basis and included in accrued liabilities on the consolidated balance sheets. Deferred income taxes reflect the tax effect of net operating loss carryforwards ("NOLs"), capital loss or tax credit carryforwards, and the net tax effects of temporary differences between the carrying amount of assets and liabilities for financial reporting and income tax purposes, as determined under enacted tax laws and rates. Valuation allowances are established if, based on the weight of available evidence, it is more likely than not that some portion or the entire deferred income tax asset will not be realized. The financial effect of changes in tax laws or rates is accounted for in the period of enactment.
Earnings Per Share	Earnings Per Share Basic earnings per share is calculated based on the weighted-average number of shares of common stock outstanding during each year. Diluted earnings per share gives effect to dilutive potential common shares outstanding during each year.
Foreign Currency Translations	Foreign Currency Translation Assets and liabilities of foreign subsidiaries are translated at current exchange rates and related revenues and expenses are translated at average rates of exchange in effect during the year. Resulting cumulative translation adjustments are recorded as a separate component of other comprehensive income (loss).
Legal Contingencies	Legal Contingencies The Company provides for legal contingencies when the liability is probable and the amount of the associated costs is reasonably estimable. The Company regularly monitors the progress of legal contingencies and revises the amounts recorded in the period in which a change in estimate occurs.
Environmental Liabilities	Environmental Liabilities The Company accrues for losses associated with environmental remediation obligations when such losses are probable and reasonably estimable. Accruals for estimated losses from environmental remediation obligations generally are recognized no later than completion of the remedial feasibility study. Such accruals are adjusted as further information develops or circumstances change. Costs of future expenditures for environmental remediation obligations are not discounted to their present value. Recoveries of environmental remediation costs from other parties are recorded as assets when their receipt is deemed probable.
New Accounting Pronouncements, Policy	In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers (Topic 606). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services, and the guidance defines a five step process to achieve this core principle. In August 2015, the FASB issued ASU No. 2015-14, which deferred the effective date of ASU No. 2014-09 by one year. The ASU, as amended, is effective for the Company's 2018 fiscal year and may be applied either (i) retrospectively to each prior reporting period presented with an election for certain specified practical expedients, or (ii) retrospectively with the cumulative effect of initially applying the ASU recognized at the date of initial application, with additional disclosure requirements. The Company is continuing to evaluate the impact of this guidance and the transition alternatives on its consolidated financial statements and, therefore, cannot reasonably estimate the impact that adoption will have on its financial condition, results of operations or cash flows. In July 2015, the FASB issued ASU No. 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory, which requires an entity to measure inventory at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The amendments do not apply to inventory that is measured using the LIFO method. On January 1, 2017, the Company began applying the inventory measurement provisions of the new ASU and such provisions did not have and are not expected to have a material impact on the Company's consolidated financial statements. In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments, which eliminates the requirement to restate prior-period financial statements for measurement-period adjustments following a business combination. The new guidance requires that the cumulative impact of a measurement-period adjustment (including the impact on prior periods) be recognized in the reporting period in which the adjustment is identified. The prior-period impact of the adjustment should either be presented separately on the face of the statement of operations or disclosed in the notes. This new guidance was effective for the Company's 2016 fiscal year. The amendments in this ASU will be applied prospectively to adjustments to provisional amounts that occur after the effective date of this ASU. The adoption of ASU No. 2015-16 did not have any impact on the Company's 2016 financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The new standard establishes a right-of-use ("ROU") model that requires a lessee to record a ROU asset and a lease liability, measured on a discounted basis, on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the statement of operations. A modified retrospective transition approach is required for capital and operating leases existing at the date of adoption, with certain practical expedients available. The Company is currently evaluating the potential impact of this new guidance, which is effective for the Company's 2019 fiscal year. In March 2016, the FASB issued ASU No. 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. This new standard simplifies the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows, among other things. The new standard is effective for the Company's 2017 fiscal year, and the Company has adopted its provisions as of January 1, 2017. The impacts of certain amendments in ASU No. 2016-09, such as those related to the treatment of tax windfalls from stock based compensation that are included in NOLs and elections made for accounting for forfeitures, are required to be adopted on a modified retrospective basis through a cumulative-effect adjustment to retained earnings. However, since the Company has utilized the majority of its NOLs at December 31, 2016 (see Note 16 - "Income Taxes"), and has elected to continue to estimate forfeitures under its current policy, there were no modified retrospective adjustments recorded upon adoption. The other provisions of ASU No. 2016-09, such as classification of certain items in the statement of cash flows, will be applied in 2017, with reclassification of prior period amounts where applicable. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The new standard changes the impairment model for most financial assets that are measured at amortized cost and certain other instruments, including trade receivables, from an incurred loss model to an expected loss model and adds certain new required disclosures. Under the expected loss model, entities will recognize estimated credit losses to be incurred over the entire contractual term of the instrument rather than delaying recognition of credit losses until it is probable the loss has been incurred. The new standard is effective for the Company's 2020 fiscal year with early adoption permitted for all entities in fiscal years beginning after December 15, 2018. The Company is currently evaluating the potential impact of this new guidance. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. This new standard provides guidance to help decrease diversity in practice in how certain cash receipts and cash payments are classified in the statement of cash flows. The amendments in ASU No. 2016-15 provide guidance on eight specific cash flow issues. The new standard is effective for the Company's 2018 fiscal year. The Company is currently evaluating the potential impact of this new guidance. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. This new standard provides guidance on the classification of restricted cash in the statement of cash flows. The amendments in ASU No. 2016-18 are effective for the Company's 2018 fiscal year. The Company is currently evaluating the potential impact of this new guidance. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. This new standard provides guidance to help determine more clearly what is a business acquisition, as opposed to an asset acquisition. The amendments provide a screen to help determine when a set of components is a business, by reducing the number of transactions in an acquisition that need to be evaluated. The new standard states that to classify the acquisition of assets as a business, there must be an input and a substantive process that jointly contribute to the ability to create outputs, with outputs being defined as the key elements of the business. If all of the fair value of the assets acquired are concentrated in a single asset group, this would not qualify as a business. The amendments in ASU No. 2017-01 are effective for the Company's 2018 fiscal year. The Company is currently evaluating the potential impact of this new guidance. In January 2017, the FASB issued ASU No. 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. This new standard simplifies subsequent measurements of goodwill by eliminating Step 2 from the goodwill impairment test. Instead, entities will perform their interim or annual goodwill impairment testing by comparing the fair value of a reporting unit with its carrying amount, and recognizing an impairment charge based on the amount that the carrying amount exceeds the reporting unit's fair value. The loss recognized should not exceed the total goodwill allocated to the reporting unit. The amendments in ASU No. 2017-04 are effective for the Company's 2020 fiscal year. The Company is currently evaluating the potential impact of this new guidance.