Significant Accounting Policies	12 Months Ended
Dec. 31, 2014
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Principles of Consolidation — OM Group, Inc. (the “Company”, “we”, “our”, “us”) is a technology-driven industrial company serving attractive global markets, including automotive systems, electronic devices, aerospace and defense, industrial and medical. We use innovative technologies to address customers' complex applications and demanding requirements. Our strategy is to grow organically through product and application innovation and new market and customer development, to grow strategically through complementary acquisitions to build-out our growth platforms, and to maximize total stockholder returns through a combination of business growth, financial discipline, optimal deployment of capital and continued operational excellence. Our objective is to deliver sustainable, profitable growth and create long-term stockholder value. The consolidated financial statements include the accounts of OM Group and its consolidated subsidiaries. We were formed in 1991 as a Delaware Corporation. Intercompany accounts and transactions have been eliminated in consolidation. Certain financial data may have been rounded. As a result of such rounding, the totals of data presented in this document may vary slightly from the actual arithmetical totals of such data. On November 24, 2014, we completed the acquisition of Ener-Tek International, Inc., which operates under the brand name Yardney Technical Products ("Yardney"), and now operates as a part of our Battery Technologies business. Based in East Greenwich, Rhode Island, Yardney is a designer, developer and manufacturer of high-performance lithium-ion and silver-zinc cells and batteries for niche applications in the defense and aerospace markets. We funded the $24.6 million acquisition price through existing cash balances. On May 31, 2013, we completed the sale of our Ultra Pure Chemicals business. The results of our Ultra Pure Chemicals business are reported as discontinued operations in the accompanying unaudited condensed consolidated financial statements and Notes to Consolidated Financial Statements for all periods presented. See note 5 - Acquisitions and Divestitures. On March 29, 2013, we completed the divestiture of our cobalt-based business. The transaction comprised the sale of the downstream portion of the business, (including its cobalt refinery assets in Kokkola, Finland) and the transfer of our 55% equity interests in the DRC-based joint venture known as GTL to the joint venture partners, subject to a security interest in our favor with respect to the joint venture's performance related to certain supply agreements. Until March 29, 2013, we consolidated the GTL joint venture because we had a controlling interest. Non-controlling interest was recorded for the remaining 45% interest. See note 5 - Acquisitions and Divestitures. The financial position, results of operations and cash flows of acquisitions are included in the Consolidated Financial Statements from the dates of acquisition. Unless otherwise indicated, all disclosures and amounts in the Notes to Consolidated Financial Statements relate to the Company's continuing operations. Use of Estimates - The preparation of financial statements, in conformity with US generally accepted accounting policies ("US GAAP"), requires management to make estimates and assumptions in certain circumstances that affect the amounts reported in the accompanying consolidated financial statements and notes. Actual results could differ from these estimates. Cash Equivalents - All highly-liquid investments, with a maturity of three months or less when purchased, are considered to be cash equivalents. Allowance for Doubtful Accounts - We have recorded an allowance for doubtful accounts to record accounts receivable at their estimated net realizable value. The allowance is based upon an analysis of historical bad debts, a review of the aging of accounts receivable and the current creditworthiness of customers. Accounts are written off against the allowance when it becomes probable that collections will not occur. Trade credit is generally extended on a short-term basis and accounts receivable generally do not bear interest. Inventories - Magnetic Technologies' inventories are valued using the average cost method. Cost of sales under the average cost method represents the weighted average cost of the items sold. We believe the average cost method provides for a better matching of inventory costs with related sales based on Magnetic Technologies' manufacturing process. Our remaining inventory is valued using First in, First out (FIFO). Inventory costs include raw materials, labor and manufacturing overhead. Inventory accounted for under the percentage-of-completion method is included in work-in-process inventory and represents accumulated contract costs less the portion of such costs allocated to delivered units. The costs attributed to units delivered are based on the estimated average cost of all units expected to be produced on a contract-by-contract basis. Changes in the price of rare earth and other materials can have a significant impact on inventory valuation. We evaluate the need for a lower of cost or market (“LCM”) adjustment to inventories based on the selling prices of our finished products generally at the end of the period. To the extent raw material prices increase subsequent to the balance sheet date, we consider these price movements in our LCM evaluation. Declines in the selling prices of our finished goods, which can result from decreases in the market price of raw materials or other factors, can result in our inventory carrying value being written down to a lower market value. Property, Plant and Equipment - Property, plant and equipment is recorded at historical cost less accumulated depreciation. Depreciation of plant and equipment, including assets recorded under capital leases, is provided by the straight-line method over the useful lives of 5 to 25 years for land improvements, 5 to 40 years for buildings and improvements, 5 to 15 years for machinery and equipment (with the majority in the range of 5 to 10 years), 5 to 10 years for furniture and fixtures and 3 to 5 years for vehicles and computers and related equipment. Leasehold improvements are depreciated over the shorter of the estimated useful life or the term of the lease. Long-lived Assets other than Goodwill - Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount may not be recoverable. Events or circumstances that would result in an impairment review primarily include operating losses, a significant change in the use of an asset, or the planned disposal or sale of the asset. The asset would be considered impaired when the future net undiscounted cash flows generated by the asset are less than its carrying value. An impairment loss would be recognized based on the amount by which the carrying value of the asset exceeds its estimated fair value. Goodwill and Intangible Assets - We evaluate the carrying value of goodwill and indefinite-lived intangible assets for impairment annually as of October 1 and between annual evaluations if changes in circumstances or the occurrence of certain events indicate potential impairment. If the carrying value of goodwill or an indefinite-lived intangible asset exceeds its fair value, an impairment loss is recognized. Intangible assets consist of (i) definite-lived assets subject to amortization and (ii) indefinite-lived intangible assets not subject to amortization. Definite-lived intangible assets consist principally of customer relationships, developed technology, know-how, capitalized software and license agreements and are being amortized using the straight-line or other appropriate method, if applicable. Indefinite-lived intangible assets consist of tradenames. Retained Liabilities of Businesses Sold - Retained liabilities of businesses sold include obligations related to our former Precious Metals Group (“PMG”), which was sold in 2003. Under terms of the sale agreement, we will reimburse the buyer of this business for certain items that become due and payable by the buyer subsequent to the sale date. Such items are principally comprised of taxes payable related to periods during which we owned PMG. The liability was $11.3 million and $12.3 million as of December 31, 2014 and 2013, respectively. Corresponding receivables related to the indemnification of the liabilities of $8.2 million and $9.1 million at December 31, 2014 and 2013, respectively, were recorded in Other non-current assets. Revenue Recognition — Except for revenue recognized under the percentage of completion method of accounting in Battery Technologies (see discussion below), we recognize revenue when persuasive evidence of an arrangement exists, unaffiliated customers take title and assume risk of loss, the sales price is fixed or determinable and collection of the related receivable is reasonably assured. Revenue recognition generally occurs upon shipment of product or usage of inventory consigned to customers. All amounts in a sales transaction billed to a customer related to shipping and handling are reported as sales. The Battery Technologies segment uses the percentage of completion method to recognize most of its revenue. Most defense contracts use the units-of-delivery method while most space contracts use the cost-to-cost method as the basis to measure progress toward completing a contract. Under the units-of-delivery method, revenues are recognized based on the contract price of units delivered. Under the cost-to-cost method, revenue is recognized based on the ratio of cost incurred compared to management's estimate of total costs expected to be incurred under the contract. The percentage of completion method requires substantial judgment on the part of management due to the duration of the contracts as well as the technical nature of the products involved. Contract revenues and cost estimates are reviewed at least quarterly and adjustments are reflected in the accounting period such amounts are determined. Billings in excess of amounts earned are deferred. Anticipated losses on contracts are recorded in full in the period in which the loss becomes evident. Cost of Goods Sold — Cost of goods sold is comprised of raw material costs, direct production, maintenance and utility costs, depreciation, other overhead costs and shipping and handling costs. Research and Development — Research and development costs are charged to expense when incurred, are included in selling, general and administrative expenses and amounted to $26.0 million, $26.3 million and $32.2 million in 2014, 2013 and 2012, respectively. These amounts do not include development and application engineering costs incurred in conjunction with fulfilling customer orders and executing projects. Accounting for Operating Leases — Lease expense is recorded on a straight-line basis. The noncancellable lease term used to calculate the amount of the straight-line expense is generally determined to be the initial lease term, including any optional renewal terms that are reasonably assured. Certain leases include escalating rent provisions and lease incentives which are recognized as lease expense on a straight-line basis over the lease term. Lease payments that depend on an existing index or rate are included in our minimum lease payments that are recognized as lease expense on a straight-line basis over the minimum lease term. Income Taxes — Deferred income taxes are provided to recognize the effect of temporary differences between financial and tax reporting. Deferred income taxes are not provided for undistributed earnings of foreign consolidated subsidiaries, to the extent such earnings are determined to be reinvested for an indefinite period of time. Foreign Currency Translation — The functional currency for most of our operating subsidiaries outside of the United States is the applicable local currency. For those operations, assets and liabilities are translated into U.S. dollars at period-ending exchange rates and revenues and expenses are translated into U.S. dollars using average exchange rates. The resulting translation adjustments are recorded as a component of Accumulated other comprehensive income (loss) in stockholders’ equity. Accordingly, foreign currency exchange gains and losses related to assets, liabilities and transactions denominated in other currencies (principally the Euro) are included in the Statements of Consolidated Operations. Derivative Instruments — We enter into derivative instruments and hedging activities to manage, where possible and economically efficient, commodity price risk, foreign currency exchange rate risk and interest rate risk related to borrowings. It is our policy to execute such instruments with creditworthy banks and not enter into derivative instruments for speculative purposes. All derivatives are reflected at their fair value and recorded in other current assets and other current liabilities as of December 31, 2013. There were no outstanding derivatives as of December 31, 2014. The accounting for the fair value of a derivative depends upon whether it has been designated as a hedge and on the type of hedging relationship. To qualify for designation in a hedging relationship, specific criteria must be met and appropriate documentation prepared. Changes in the fair values of derivatives not designated in a hedging relationship are recognized in earnings. From time to time we employ derivative instruments in connection with purchases and sales of inventory in order to establish a fixed margin and mitigate the risk of price volatility. Some customers request fixed pricing and we may use a derivative to mitigate price risk. While this hedging may limit our ability to participate in gains from favorable commodity price fluctuations, it eliminates the risk of loss from adverse commodity price fluctuations. Periodically, we enter into certain derivative instruments designated as cash flow hedges. For these hedges, the effective portion of the gain or loss from the financial instrument is initially reported as a component of Accumulated other comprehensive income (loss) in stockholders’ equity and subsequently reclassified into earnings in the same line as the hedged item in the same period or periods during which the hedged item affects earnings.

Significant Accounting Policies

Principles of Consolidation — OM Group, Inc. (the “Company”, “we”, “our”, “us”) is a technology-driven industrial company serving attractive global markets, including automotive systems, electronic devices, aerospace and defense, industrial and medical. We use innovative technologies to address customers' complex applications and demanding requirements. Our strategy is to grow organically through product and application innovation and new market and customer development, to grow strategically through complementary acquisitions to build-out our growth platforms, and to maximize total stockholder returns through a combination of business growth, financial discipline, optimal deployment of capital and continued operational excellence. Our objective is to deliver sustainable, profitable growth and create long-term stockholder value. The consolidated financial statements include the accounts of OM Group and its consolidated subsidiaries. We were formed in 1991 as a Delaware Corporation. Intercompany accounts and transactions have been eliminated in consolidation.

Certain financial data may have been rounded. As a result of such rounding, the totals of data presented in this document may vary slightly from the actual arithmetical totals of such data.

On November 24, 2014, we completed the acquisition of Ener-Tek International, Inc., which operates under the brand name Yardney Technical Products ("Yardney"), and now operates as a part of our Battery Technologies business. Based in East Greenwich, Rhode Island, Yardney is a designer, developer and manufacturer of high-performance lithium-ion and silver-zinc cells and batteries for niche applications in the defense and aerospace markets. We funded the $24.6 million acquisition price through existing cash balances.

On May 31, 2013, we completed the sale of our Ultra Pure Chemicals business. The results of our Ultra Pure Chemicals business are reported as discontinued operations in the accompanying unaudited condensed consolidated financial statements and Notes to Consolidated Financial Statements for all periods presented. See note 5 - Acquisitions and Divestitures.

On March 29, 2013, we completed the divestiture of our cobalt-based business. The transaction comprised the sale of the downstream portion of the business, (including its cobalt refinery assets in Kokkola, Finland) and the transfer of our 55% equity interests in the DRC-based joint venture known as GTL to the joint venture partners, subject to a security interest in our favor with respect to the joint venture's performance related to certain supply agreements. Until March 29, 2013, we consolidated the GTL joint venture because we had a controlling interest. Non-controlling interest was recorded for the remaining 45% interest. See note 5 - Acquisitions and Divestitures.

The financial position, results of operations and cash flows of acquisitions are included in the Consolidated Financial Statements from the dates of acquisition.

Unless otherwise indicated, all disclosures and amounts in the Notes to Consolidated Financial Statements relate to the Company's continuing operations.

Use of Estimates - The preparation of financial statements, in conformity with US generally accepted accounting policies ("US GAAP"), requires management to make estimates and assumptions in certain circumstances that affect the amounts reported in the accompanying consolidated financial statements and notes. Actual results could differ from these estimates.

Cash Equivalents - All highly-liquid investments, with a maturity of three months or less when purchased, are considered to be cash equivalents.

Allowance for Doubtful Accounts - We have recorded an allowance for doubtful accounts to record accounts receivable at their estimated net realizable value. The allowance is based upon an analysis of historical bad debts, a review of the aging of accounts receivable and the current creditworthiness of customers. Accounts are written off against the allowance when it becomes probable that collections will not occur. Trade credit is generally extended on a short-term basis and accounts receivable generally do not bear interest.

Inventories - Magnetic Technologies' inventories are valued using the average cost method. Cost of sales under the average cost method represents the weighted average cost of the items sold. We believe the average cost method provides for a better matching of inventory costs with related sales based on Magnetic Technologies' manufacturing process. Our remaining inventory is valued using First in, First out (FIFO). Inventory costs include raw materials, labor and manufacturing overhead. Inventory accounted for under the percentage-of-completion method is included in work-in-process inventory and represents accumulated contract costs less the portion of such costs allocated to delivered units. The costs attributed to units delivered are based on the estimated average cost of all units expected to be produced on a contract-by-contract basis.

Changes in the price of rare earth and other materials can have a significant impact on inventory valuation. We evaluate the need for a lower of cost or market (“LCM”) adjustment to inventories based on the selling prices of our finished products generally at the end of the period. To the extent raw material prices increase subsequent to the balance sheet date, we consider these price movements in our LCM evaluation. Declines in the selling prices of our finished goods, which can result from decreases in the market price of raw materials or other factors, can result in our inventory carrying value being written down to a lower market value.

Property, Plant and Equipment - Property, plant and equipment is recorded at historical cost less accumulated depreciation. Depreciation of plant and equipment, including assets recorded under capital leases, is provided by the straight-line method over the useful lives of 5 to 25 years for land improvements, 5 to 40 years for buildings and improvements, 5 to 15 years for machinery and equipment (with the majority in the range of 5 to 10 years), 5 to 10 years for furniture and fixtures and 3 to 5 years for vehicles and computers and related equipment. Leasehold improvements are depreciated over the shorter of the estimated useful life or the term of the lease.

Long-lived Assets other than Goodwill - Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount may not be recoverable. Events or circumstances that would result in an impairment review primarily include operating losses, a significant change in the use of an asset, or the planned disposal or sale of the asset. The asset would be considered impaired when the future net undiscounted cash flows generated by the asset are less than its carrying value. An impairment loss would be recognized based on the amount by which the carrying value of the asset exceeds its estimated fair value.

Goodwill and Intangible Assets - We evaluate the carrying value of goodwill and indefinite-lived intangible assets for impairment annually as of October 1 and between annual evaluations if changes in circumstances or the occurrence of certain events indicate potential impairment. If the carrying value of goodwill or an indefinite-lived intangible asset exceeds its fair value, an impairment loss is recognized.

Intangible assets consist of (i) definite-lived assets subject to amortization and (ii) indefinite-lived intangible assets not subject to amortization. Definite-lived intangible assets consist principally of customer relationships, developed technology, know-how, capitalized software and license agreements and are being amortized using the straight-line or other appropriate method, if applicable. Indefinite-lived intangible assets consist of tradenames.

Retained Liabilities of Businesses Sold - Retained liabilities of businesses sold include obligations related to our former Precious Metals Group (“PMG”), which was sold in 2003. Under terms of the sale agreement, we will reimburse the buyer of this business for certain items that become due and payable by the buyer subsequent to the sale date. Such items are principally comprised of taxes payable related to periods during which we owned PMG. The liability was $11.3 million and $12.3 million as of December 31, 2014 and 2013, respectively. Corresponding receivables related to the indemnification of the liabilities of $8.2 million and $9.1 million at December 31, 2014 and 2013, respectively, were recorded in Other non-current assets.

Revenue Recognition — Except for revenue recognized under the percentage of completion method of accounting in Battery Technologies (see discussion below), we recognize revenue when persuasive evidence of an arrangement exists, unaffiliated customers take title and assume risk of loss, the sales price is fixed or determinable and collection of the related receivable is reasonably assured. Revenue recognition generally occurs upon shipment of product or usage of inventory consigned to customers. All amounts in a sales transaction billed to a customer related to shipping and handling are reported as sales.

The Battery Technologies segment uses the percentage of completion method to recognize most of its revenue. Most defense contracts use the units-of-delivery method while most space contracts use the cost-to-cost method as the basis to measure progress toward completing a contract. Under the units-of-delivery method, revenues are recognized based on the contract price of units delivered. Under the cost-to-cost method, revenue is recognized based on the ratio of cost incurred compared to management's estimate of total costs expected to be incurred under the contract. The percentage of completion method requires substantial judgment on the part of management due to the duration of the contracts as well as the technical nature of the products involved. Contract revenues and cost estimates are reviewed at least quarterly and adjustments are reflected in the accounting period such amounts are determined. Billings in excess of amounts earned are deferred. Anticipated losses on contracts are recorded in full in the period in which the loss becomes evident.

Cost of Goods Sold — Cost of goods sold is comprised of raw material costs, direct production, maintenance and utility costs, depreciation, other overhead costs and shipping and handling costs.

Research and Development — Research and development costs are charged to expense when incurred, are included in selling, general and administrative expenses and amounted to $26.0 million, $26.3 million and $32.2 million in 2014, 2013 and 2012, respectively. These amounts do not include development and application engineering costs incurred in conjunction with fulfilling customer orders and executing projects.

Accounting for Operating Leases — Lease expense is recorded on a straight-line basis. The noncancellable lease term used to calculate the amount of the straight-line expense is generally determined to be the initial lease term, including any optional renewal terms that are reasonably assured. Certain leases include escalating rent provisions and lease incentives which are recognized as lease expense on a straight-line basis over the lease term. Lease payments that depend on an existing index or rate are included in our minimum lease payments that are recognized as lease expense on a straight-line basis over the minimum lease term.

Income Taxes — Deferred income taxes are provided to recognize the effect of temporary differences between financial and tax reporting. Deferred income taxes are not provided for undistributed earnings of foreign consolidated subsidiaries, to the extent such earnings are determined to be reinvested for an indefinite period of time.

Foreign Currency Translation — The functional currency for most of our operating subsidiaries outside of the United States is the applicable local currency. For those operations, assets and liabilities are translated into U.S. dollars at period-ending exchange rates and revenues and expenses are translated into U.S. dollars using average exchange rates. The resulting translation adjustments are recorded as a component of Accumulated other comprehensive income (loss) in stockholders’ equity. Accordingly, foreign currency exchange gains and losses related to assets, liabilities and transactions denominated in other currencies (principally the Euro) are included in the Statements of Consolidated Operations.

Derivative Instruments — We enter into derivative instruments and hedging activities to manage, where possible and economically efficient, commodity price risk, foreign currency exchange rate risk and interest rate risk related to borrowings. It is our policy to execute such instruments with creditworthy banks and not enter into derivative instruments for speculative purposes. All derivatives are reflected at their fair value and recorded in other current assets and other current liabilities as of December 31, 2013. There were no outstanding derivatives as of December 31, 2014. The accounting for the fair value of a derivative depends upon whether it has been designated as a hedge and on the type of hedging relationship. To qualify for designation in a hedging relationship, specific criteria must be met and appropriate documentation prepared. Changes in the fair values of derivatives not designated in a hedging relationship are recognized in earnings.

From time to time we employ derivative instruments in connection with purchases and sales of inventory in order to establish a fixed margin and mitigate the risk of price volatility. Some customers request fixed pricing and we may use a derivative to mitigate price risk. While this hedging may limit our ability to participate in gains from favorable commodity price fluctuations, it eliminates the risk of loss from adverse commodity price fluctuations.

Periodically, we enter into certain derivative instruments designated as cash flow hedges. For these hedges, the effective portion of the gain or loss from the financial instrument is initially reported as a component of Accumulated other comprehensive income (loss) in stockholders’ equity and subsequently reclassified into earnings in the same line as the hedged item in the same period or periods during which the hedged item affects earnings.