Om 10-Q 1 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014	Jul. 31, 2014
Document And Entity Information [Abstract]	'	'
Entity Registrant Name	'OM GROUP INC	'
Entity Central Index Key	'0000899723	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	31,780,433

Unaudited_Condensed_Consolidat

Unaudited Condensed Consolidated Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Current assets	'	'
Cash and cash equivalents	$114.30	$118.40
Accounts receivable, less allowance of $2.4 in 2014 and $3.9 in 2013	170.5	150.7
Inventories	243.8	240.9
Other current assets	19.4	32.3
Total current assets	548	542.3
Property, plant and equipment, net	328.6	345.6
Goodwill	431.6	432.7
Intangible assets, net	388.6	403
Other non-current assets	58.5	59.5
Total assets	1,755.30	1,783.10
Current liabilities	'	'
Accounts payable	87.3	93.6
Accrued employee costs	35.4	36.2
Purchase price of VAC payable to seller	52.6	52.5
Other current liabilities	54.3	63.4
Total current liabilities	229.6	245.7
Deferred income taxes	101.3	102.5
Pension liabilities	218.4	220.5
Purchase price of VAC payable to seller	11.3	11.3
Other non-current liabilities	38.7	43.3
Stockholders’ equity:	'	'
Preferred stock, $.01 par value: Authorized 2,000,000 shares, no shares issued or outstanding	0	0
Common stock, $.01 par value: Authorized 90,000,000 shares; 32,960,027 shares issued in 2014 and 32,304,490 shares issued in 2013	0.3	0.3
Capital in excess of par value	644.2	639.8
Retained earnings	592.5	587.2
Treasury stock (1,175,984 shares in 2014 and 825,956 shares in 2013, at cost)	-33	-22.3
Accumulated other comprehensive loss	-48	-45.2
Total equity	1,156	1,159.80
Total liabilities and equity	$1,755.30	$1,783.10

Unaudited_Condensed_Consolidat1

Unaudited Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Allowance for Doubtful Accounts Receivable, Current	$2,424	$3,884
Preferred Stock, Par or Stated Value Per Share (in usd per share)	$0.01	$0.01
Preferred Stock, Shares Authorized (in shares)	2,000,000	2,000,000
Preferred Stock, Shares Issued (in shares)	0	0
Preferred Stock, Shares Outstanding (in shares)	0	0
Common Stock, Par or Stated Value Per Share (in usd per share)	$0.01	$0.01
Common Stock, Shares Authorized (in shares)	90,000,000	90,000,000
Common Stock, Shares, Issued (in shares)	32,960,027	32,304,490
Treasury Stock, Shares (in shares)	1,175,984	825,956

Unaudited_Condensed_Statements

Unaudited Condensed Statements of Consolidated Operations (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]	'	'	'	'
Net sales	$297.50	$279.40	$559.20	$621.10
Cost of goods sold	234.4	215.6	434.2	483.1
Gross profit	63.1	63.8	125	138
Selling, general and administrative expenses	53.2	54.6	106.6	114.7
Operating profit	9.9	9.2	18.4	23.3
Other expense:	'	'	'	'
Interest expense	-0.6	-1.8	-1.3	-9.5
Foreign exchange (loss) gain	-0.9	2.8	-1.2	0.2
Loss on divestiture of Advanced Materials business	-0.8	-0.5	-1	-112.1
Other, net	-0.7	0.3	-1.4	-0.3
Income (loss) from continuing operations before income tax expense	6.9	10	13.5	-98.4
Income tax expense	1.8	1.9	3.1	4.5
Income (loss) from continuing operations, net of tax	5.1	8.1	10.4	-102.9
Loss from discontinued operations, net of tax	-0.3	-11.4	-0.3	-11.9
Consolidated net income (loss)	4.8	-3.3	10.1	-114.8
Net loss attributable to noncontrolling interests	0	0	0	1.7
Net income (loss) attributable to OM Group, Inc. common stockholders	4.8	-3.3	10.1	-113.1
Earnings (loss) per common share — basic:	'	'	'	'
Income (loss) from continuing operations attributable to OM Group, Inc. common stockholders - basic (in dollars per share)	$0.16	$0.26	$0.33	($3.19)
Loss from discontinued operations attributable to OM Group, Inc. common stockholders - basic (net of tax) (in dollars per share)	($0.01)	($0.37)	($0.01)	($0.38)
Net income (loss) attributable to OM Group, Inc. common stockholders (in dollars per share)	$0.15	($0.11)	$0.32	($3.57)
Earnings (loss) per common share — assuming dilution:	'	'	'	'
Income (loss) from continuing operations attributable to OM Group, Inc. common stockholders (in dollars per share)	$0.16	$0.26	$0.33	($3.19)
Loss from discontinued operations attributable to OM Group, Inc. common stockholders (in dollars per share)	($0.01)	($0.37)	($0.02)	($0.38)
Net income (loss) attributable to OM Group, Inc. common stockholders (in dollars per share)	$0.15	($0.11)	$0.31	($3.57)
Weighted average shares outstanding	'	'	'	'
Basic (in shares)	31.5	31.5	31.5	31.7
Assuming dilution (in shares)	31.8	31.6	31.9	31.7
Dividends declared per common share (in dollars per share)	$0.08	$0	$0.15	$0
Amounts attributable to OM Group, Inc. common shareholders:	'	'	'	'
Income (loss) from continuing operations, net of tax	5.1	8.1	10.4	-101.2
Loss from discontinued operations, net of tax	-0.3	-11.4	-0.3	-11.9
Net income (loss) attributable to OM Group, Inc. common stockholders	$4.80	($3.30)	$10.10	($113.10)

Unaudited_Statements_of_Consol

Unaudited Statements of Consolidated Comprehensive Income (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Consolidated net income (loss)	$4.80	($3.30)	$10.10	($114.80)
Foreign currency translation adjustments	-1.3	9.1	-3.2	-16.3
Reclassification of foreign currency translation adjustment related to the discontinued operations into earnings	0	8.8	0	8.8
Reclassification of hedging activities into earnings, net of tax	0.1	0	0.2	0
Unrealized loss on cash flow hedges, net of tax	0	-0.1	0	-0.1
Pension adjustment	0.1	0.5	0.2	0.6
Net change in accumulated other comprehensive income	-1.1	18.3	-2.8	-7
Comprehensive income (loss)	3.7	15	7.3	-121.8
Comprehensive loss attributable to noncontrolling interests	0	0	0	1.7
Comprehensive income (loss) attributable to OM Group, Inc.	$3.70	$15	$7.30	($120.10)

Unaudited_Condensed_Statements1

Unaudited Condensed Statements of Consolidated Cash Flows (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
			UPC Business [Member]	UPC Business [Member]
Operating activities	'	'	'	'
Consolidated net income (loss)	$10.10	($114.80)	'	'
Adjustments to reconcile consolidated net income (loss) to net cash used for operating activities:	'	'	'	'
Loss from discontinued operations	0.3	11.9	'	'
Depreciation and amortization	36.4	38.1	'	'
Amortization of deferred financing fees	0.5	2	'	'
Share-based compensation expense	4.4	3.2	'	'
Foreign exchange loss (gain)	1.2	-0.2	'	'
Loss on divestiture of Advanced Materials business	1	112.1	'	'
Other non-cash items	1.2	5.8	'	'
Changes in operating assets and liabilities, excluding the effect of divestitures:	'	'	'	'
Accounts receivable	-20.3	-34.7	'	'
Inventories	-4.5	16.8	'	'
Accounts payable	-6.1	1.6	'	'
Accrued tax	-2.6	-23.9	'	'
Other, net	0.2	-24.7	'	'
Net cash provided by (used for) operating activities	21.8	-6.8	'	'
Investing activities	'	'	'	'
Expenditures for property, plant and equipment	-10.8	-21.3	'	'
Proceeds from divestiture	'	'	0	63.3
Proceeds from sale of property	1	0	'	'
Net cash (used for) provided by investing activities	-9.8	344.1	'	'
Financing activities	'	'	'	'
Payments of long-term debt	0	-466.5	'	'
Dividends paid	-4.8	0	'	'
Proceeds from exercise of stock options	0.5	1	'	'
Debt issuance costs	-0.1	0	'	'
Payment related to surrendered shares	-0.7	-0.6	'	'
Share repurchases	-10	-14.1	'	'
Net cash used for financing activities	-15.1	-480.2	'	'
Effect of exchange rate changes on cash	-0.2	-1.4	'	'
Cash and cash equivalents	'	'	'	'
Decrease from continuing operations	-3.3	-144.3	'	'
Discontinued operations - net cash used by operating activities	-0.8	-0.3	'	'
Discontinued operations - net cash used for investing activities	0	-2.4	'	'
Balance at the beginning of the period	118.4	227.6	'	'
Balance at the end of the period	$114.30	$80.60	'	'

Basis_of_Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	OM Group, Inc. ("OM Group", the “Company”, “we”, “our”, “us”) is a technology-based industrial growth company serving attractive global markets, including automotive systems, electronic devices, aerospace, industrial and renewable energy. We use innovative technologies to address customers' complex applications and demanding requirements. Our strategy is to grow organically through product innovation and new market and customer development; to grow strategically through synergistic acquisitions; and to maximize total stockholder return 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 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 for all periods presented. See note 4 - 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 favor of OM Group 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. Noncontrolling interest was recorded for the remaining 45% interest. See note 4 - Acquisitions and Divestitures.
	These financial statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and the instructions to Form 10-Q and do not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of our financial position at June 30, 2014 and the results of our income (loss), comprehensive income (loss) and cash flows for the six months ended June 30, 2014 and 2013 have been included. The balance sheet at December 31, 2013 has been derived from the audited consolidated financial statements at that date but does not include all of the information or notes required by U.S. generally accepted accounting principles for complete financial statements. Past operating results are not necessarily indicative of the results which may occur in future periods, and the interim period results are not necessarily indicative of the results to be expected for the full year. These Unaudited Condensed Consolidated Financial Statements should be read in conjunction with the consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2013.

Recently_Issued_Accounting_Gui

Recently Issued Accounting Guidance	6 Months Ended
	Jun. 30, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Recently Issued Accounting Guidance	'
	Recently Issued Accounting Guidance
	Accounting Guidance adopted in 2014
	In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” (“ASU 2014-09”). The update amends the guidance for revenue recognition to replace numerous, industry-specific requirements and converges areas under this topic with those of the International Financial Reporting Standards. The amendments are effective for reporting periods beginning after December 15, 2016, and early adoption is prohibited. Entities can transition to the standard either retrospectively or as a cumulative-effect adjustment as of the date of adoption. We are currently assessing the impact the adoption of ASU 2014-09 may have on our results of operations or financial position.
	In July 2013, the FASB issued ASU 2013-11 Presentation of Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward exists. The update requires companies to offset a liability recorded for an unrecognized tax benefit against a related deferred tax asset of a net operating loss carryforward, a similar tax loss or a tax credit carryforward if such settlement is required or expected in the event the uncertain tax position is disallowed. The amendments are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. We adopted this guidance as of March 31, 2014 and reclassified a portion of our uncertain tax position accrual to net against the related deferred tax assets. Such adoption did not have an effect on our results of operations or financial position.

Inventories

Inventories	6 Months Ended
	Jun. 30, 2014
Inventory, Net [Abstract]	'
Inventories	'
	Inventories
	Inventories consist of the following:
		June 30,		December 31,
		2014		2013
	Raw materials and supplies	$	88.1	$	83.3
	Work-in-process	115.1		122.2
	Finished goods	40.6		35.4
		$	243.8	$	240.9

Acquisitions_and_Divestitures

Acquisitions and Divestitures	6 Months Ended
	Jun. 30, 2014
Business Combinations [Abstract]	'
Acquisitions and Divestitures	'
	Acquisitions and Divestitures
	(a) Acquisitions
	VAC
	Our Magnetic Technologies segment consists of VAC Holding GmbH ("VAC"), which we acquired in 2011. The total purchase price of $812.2 million included cash consideration of $686.2 million, withheld consideration of $86.3 million, and the issuance of Company shares valued at $39.7 million. The withheld consideration relates to potential indemnification claims made by OM Group within two years of the closing date of the acquisition with certain exceptions related to tax matters. In August 2013, we remitted a payment of $23.0 million to the seller of VAC. We remain in discussions with the seller regarding the remainder of the withheld consideration which covers unresolved claims.
	(b) Divestitures
	Advanced Materials
	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 equity interests in the DRC-based joint venture known as GTL to the joint venture partners, subject to a security interest in favor of OM Group with respect to the joint venture's performance related to certain supply arrangements.
	In connection with this transaction we received cash proceeds of $329 million. We received $302 million of net proceeds at closing and additional proceeds of $27 million as an adjustment to the purchase price based on a post-closing analysis of the closing balance sheet in July 2013. Including the adjustment to the purchase price, a loss of $112 million was recorded on the divestiture, which included a $10 million write-off of deferred financing fees related to the required debt pre-payment, a reserve for a note receivable from joint venture partner of $16 million and transaction expenses of $9 million. In the second quarter 2014, we incurred legal costs related to a post-close legal matter and recorded an additional loss of $0.8 million.
	The sale agreement for the downstream portion of the business also provides for potential future additional cash consideration of up to $110 million based on the business achieving certain revenue targets over a period of three years. Using our projected trends of cobalt prices and volumes at the time of the sale, no value was assigned to the potential future cash consideration while calculating the loss on the divestiture. Based on our projected trends of cobalt prices and volumes, we do not believe it is probable that the business will meet the revenue targets.
	Following the sale, to assist in the transition of the downstream business, we entered into two agreements with the buyer pursuant to which: (1) we act as intermediary in a supply agreement between GTL and the buyer, in back-to-back arrangements for a period of at least two years, subject to delivery of 7,000 MT of cobalt feed and extendable for up to an additional six months in order to deliver 7,000 MT of cobalt feed; and, (2) we served as the U.S. distributor for refined cobalt products in primarily back-to-back arrangements until December 31, 2013. These agreements have minimal effect on our results of operations or cash flow and will be reported in the Advanced Materials segment until both agreements expire or are terminated.
	Ultra Pure Chemicals
	On May 31, 2013, we completed the sale of our Ultra Pure Chemicals (UPC) business. In connection with this transaction we received cash proceeds of $63 million, which included an estimated $3 million working capital adjustment. A loss, net of tax, of $9.8 million was recorded on the divestiture at the time of sale, which included a gain of $1.5 million on the sale of net assets offset by the realization of a loss in accumulated other comprehensive income of $8.8 million, a $1.5 million write-off of deferred financing fees related to the required debt pre-payment and transaction expenses of $1.0 million. In the second quarter 2014, we settled the outstanding working capital items and recorded an additional loss of $0.2 million.
	The results of our UPC business are reported in discontinued operations in the accompanying unaudited condensed consolidated financial statements for all periods prior to the UPC sale.  As required, annual interest expense of $1.0 million for the period ending December 31, 2013, related to the debt repaid with the proceeds from the sale of the business was allocated to discontinued operations for all periods prior to the UPC sale.
	A summary of our discontinued operations activity is as follows:
		Three Months Ended June 30						Six Months Ended June 30
		2014			2013			2014			2013
	Net Sales	$	—		$	16		$	—		$	38.5
	Loss from operations of divested business (net of tax)	$	(0.1	)	$	(1.6	)	$	(0.1	)	$	(2.1	)
	Loss on disposal of business (net of tax)	(0.2		)	(9.8		)	(0.2		)	(9.8		)
	Loss from discontinued operations (net of tax)	$	(0.3	)	$	(11.4	)	$	(0.3	)	$	(11.9	)
	Loss per share from discontinued operations (net of tax):
	Basic	$	(0.01	)	$	(0.37	)	$	(0.01	)	$	(0.38	)
	Diluted	$	(0.01	)	$	(0.37	)	$	(0.01	)	$	(0.38	)

Debt

Debt	6 Months Ended
	Jun. 30, 2014
Debt Instruments [Abstract]	'
Debt	'
	Debt
	On September 4, 2013 we entered into a five-year Senior Secured Revolving Credit Facility (“the Facility”), and terminated our previous credit facility dated August 2, 2011 that was scheduled to expire in August 2016. The Facility provides for $350 million of revolving borrowing capacity and includes an expansion option of up to an additional $150 million, subject to certain conditions. The borrowers under the agreement are the Company, Harko C.V. (“Harko”), a limited partnership organized under the laws of the Netherlands, and VAC Germany GmbH (“VAC”), a limited liability company under the laws of Germany. Harko and VAC are wholly-owned subsidiaries of the Company. The Facility matures on September 4, 2018.
	The obligations of the Company under the Facility are guaranteed by certain of the Company’s material U.S. subsidiaries. The obligations of Harko and VAC under the Facility are guaranteed by the Company and certain of the Company’s material subsidiaries, subject to certain exceptions including financial assistance limitations in certain foreign jurisdictions. In addition, the obligations of the Company under the Facility are secured by a first priority security interest in substantially all of the existing and future personal property of the Company and certain of the Company’s material U.S. subsidiaries, including 65% of the voting capital stock of certain of the Company’s direct foreign subsidiaries. The obligations of Harko and VAC under the Facility are secured by a first priority security interest in certain of the existing and future personal property of Harko, VAC and certain of the Company’s subsidiaries and a 100% pledge of the voting capital stock of certain of the Company’s subsidiaries, subject to certain exceptions, including financial assistance limitations in certain foreign jurisdictions.
	The interest rates applicable to loans under the Facility will be at our option and equal to either a base rate or a LIBOR rate, in each case plus an applicable margin percentage. The base rate will be the highest of (i) the federal funds rate plus 0.50%, (ii) the prime rate or (iii) the LIBOR rate with a maturity of one month plus 1.00%. The applicable margin percentage is based on the leverage ratio of the Company. The range of the applicable margin percentage is 1.125% to 2.000% in the case of LIBOR advances and 0.125% to 1.000% in the case of base rate advances.
	The Facility contains customary representations and warranties and certain covenants that limit the ability of the Company and its restricted subsidiaries to, among other things: (i) incur or guarantee additional indebtedness; (ii) redeem, repurchase or pay distributions on capital stock or redeem or repurchase subordinated debt; (iii) make investments; (iv) sell assets; (v) enter into agreements that restrict distributions or other payments from restricted subsidiaries to the Company; (vi) incur or suffer to exist liens securing indebtedness; (vii) consolidate, merge or transfer all or substantially all of their assets; and (viii) engage in transactions with affiliates. In addition, the Facility contains financial covenants that limit capital expenditures in any fiscal year and that measure (i) the ratio of the Company’s total funded indebtedness net of certain cash to the amount of the Company’s consolidated EBITDA and (ii) the ratio of the amount of the Company’s consolidated EBITDA to the Company’s cash interest expense, as defined in the agreement.
	As of June 30, 2014, we have no obligations outstanding under the Facility, and we are in compliance with all of the covenants.

Derivative_Instruments

Derivative Instruments	6 Months Ended
	Jun. 30, 2014
Derivative Instruments and Hedges, Assets [Abstract]	'
Derivative Instruments	'
	Derivative Instruments
	Interest Rate Risk
	From time to time we have utilized interest rate swap agreements to partially reduce risks related to variable rate financing agreements that are subject to changes in the market rate of interest.
	We had interest rate swaps with notional values that totaled $114.5 million at March 31, 2013. Following the full repayment of the Term B facility at the end of March 2013, we elected in April 2013 to terminate all the remaining interest swap contracts. The AOCI at the time of the termination represented an immaterial cumulative loss related to these contracts, which was reclassified to earnings in the second quarter 2013. There was no hedge ineffectiveness in the six months ended June 30, 2013 for these hedges.
	Commodity Price Risk
	In May 2013, we entered into nickel forward derivative contracts to establish a fixed margin and mitigate the risk of price volatility related to certain sales expected in 2013 and 2014 of nickel-containing finished products that were priced on a formula that included a fixed nickel price component. These forward derivative contracts were designated as cash flow hedges for accounting purposes and were settled during the second quarter 2014. There was no hedge ineffectiveness in the six months ended June 30, 2014 for these hedges.

Fair_Value_Disclosures

Fair Value Disclosures	6 Months Ended
	Jun. 30, 2014
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]	'
Fair Value Disclosures	'
	Fair Value Disclosures
	The following table shows our assets and liabilities accounted for at fair value on a recurring basis:
					Fair Value Measurements at Reporting Date Using
					Quoted Prices in	Significant Other	Significant
					Active Markets for	Observable Inputs	Unobservable Inputs
					Identical Assets
	Description		30-Jun-14		(Level 1)	(Level 2)	(Level 3)
	Liabilities:
	Contingent consideration payable		1.5		—	—	1.5
	Our valuation techniques and Level 3 inputs used to estimate the fair value of the contingent consideration payable in connection with our acquisition of Rahu Catalytics Limited ("Rahu") are described below. There were no transfers into or out of Levels 1, 2 or 3 in 2013 or 2014.
	The following table summarizes changes in Level 3 liabilities measured at fair value on a recurring basis:
			Contingent Consideration
	Fair Value at	31-Dec-13	$	1.4
	Accretion expense		0.1
	Foreign exchange		—
	Fair Value at	30-Jun-14	$	1.5
	We acquired Rahu on December 22, 2011. The purchase price included contingent consideration of up to an additional €20.0 million ($27.3 million at June 30, 2014) based on achieving certain volume targets over a fifteen year period ending on December 31, 2026. We estimated the fair value of the contingent consideration using probability-weighted expected future cash flows and applied a discount rate that appropriately captures a market participant's view of the risk associated with the contingent consideration. Contingent consideration is included in Other non-current liabilities in the Unaudited Condensed Consolidated Balance Sheet. The valuation of the contingent consideration is classified utilizing Level 3 inputs consistent with assumptions which would be made by other market participants. There are many factors that could impact the likelihood that we will pay the contingent consideration and therefore its value, including overall economic conditions and our ability to drive sales volumes as planned. A change in a market participant view of risks could also impact the value of the contingent consideration.
	We also hold financial instruments consisting of cash, accounts receivable, and accounts payable. The carrying amounts of cash, accounts receivable, and accounts payable approximate fair value due to the short-term maturities of these instruments. Long-term debt outstanding at any time during 2013 had a fair value based on quoted market prices in previous periods, which are Level 1 inputs. There was no long-term debt outstanding as of June 30, 2014. Outstanding derivative instruments were recorded at fair value as indicated above. There were no outstanding derivative instruments as of June 30, 2014.

Income_Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	We file income tax returns in the U.S. federal jurisdiction, and various state and foreign jurisdictions. Our major tax jurisdictions include the U.S. and Germany. With few exceptions, we are no longer subject to U.S. federal, state and local, or non-U.S. income tax examinations by tax authorities for years before 2006. Finnish tax authorities completed the examination of our Finnish tax returns for the years 2007-2011.  VAC's German tax returns have been audited through 2005. We are indemnified, subject to certain limitations, for any pre-acquisition income tax liabilities of VAC. German tax authorities are currently examining VAC's income tax returns for the years 2006-2011.
	As required under ASC 740, our interim income tax provision is based on the application of an estimated annual effective income tax rate applied to year-to-date ordinary income from continuing operations before income tax expense. In determining the estimated annual effective income tax rate, we analyze various factors, including forecasts of projected annual earnings (including specific subsidiaries projected to have pretax income and pretax losses), taxing jurisdictions in which the earnings will be generated, our ability to use tax credits and net operating loss carryforwards, and available tax planning alternatives. We evaluate the estimated annual effective income tax rate on a quarterly basis based on current and forecasted earnings by tax jurisdiction, including changes in the Company's structure. The estimated annual effective income tax rate may be significantly impacted by changes to the mix of forecasted earnings by tax jurisdiction. The tax effects of adjustments to the estimated annual effective income tax rate are recorded in the period such estimates are revised. The tax effects of discrete items, including the effect of changes in tax laws, tax rates, certain circumstances with respect to valuation allowances or other unusual or non-recurring items, are reflected in the period in which they occur as an addition to, or reduction from, the income tax provision, rather than included in the estimated annual effective income tax rate.
	Income (loss) from continuing operations before income tax expense consists of the following:
		Three Months Ended June 30						Six Months Ended June 30
		2014			2013			2014			2013
	United States	$	0.6		$	0.2		$	(2.3	)	$	(3.7	)
	Outside the United States	6.3			9.8			15.8			(94.7		)
	Income (loss) from continuing operations before income tax expense	$	6.9		$	10		$	13.5		$	(98.4	)
	Effective Income Tax Rate	25.8		%	18.7		%	23.3		%	(4.5		)%
	The effective income tax rates for the three months ended June 30, 2014 and June 30, 2013 are lower than the U.S. statutory tax rate primarily due to income earned in tax jurisdictions with lower statutory rates than the U.S. (primarily Germany, Finland, Malaysia and Taiwan) and our financing structure, partially offset by losses in certain jurisdictions (including the U.S.) with no corresponding tax benefit, which were higher in the three months ended June 30, 2014 than the three months ended June 30, 2013.
	As of June 30, 2014, we have provided a valuation allowance against certain jurisdictions’ deferred tax assets. Realization of deferred tax assets is dependent on generating sufficient taxable income within the carryback or carry forward period under the relevant tax laws.

Defined_Benefit_Plans

Defined Benefit Plans	6 Months Ended
	Jun. 30, 2014
Pension and Other Postretirement Benefit Expense [Abstract]	'
Defined Benefit Plans	'
	Defined Benefit Plans
	At June 30, 2014 and December 31, 2013, we had pension liabilities of $227.9 million and $230.0 million, respectively, the majority of which were assumed in the 2011 VAC acquisition and the 2010 EaglePicher Technologies acquisition.
	Set forth below is a detail of the net periodic pension expense for the U.S. defined benefit plans:
		Three Months Ended June 30						Six Months Ended June 30
		2014			2013			2014			2013
	Service cost	$	0.3		$	0.3		$	0.6		$	0.6
	Interest cost	2.3			2.1			4.7			4.2
	Amortization of unrecognized net loss	0.1			0.2			0.2			0.4
	Expected return on plan assets	(2.6		)	(2.7		)	(5.1		)	(5.2		)
	Total expense	$	0.1		$	(0.1	)	$	0.4		$	—
	Set forth below is a detail of the net periodic pension expense for the VAC defined benefit plans:
		Three Months Ended June 30						Six Months Ended June 30
		2014			2013			2014			2013
	Service cost	$	1.7		$	1.2		$	3.4		$	2.4
	Interest cost	1.5			1.5			3.1			2.9
	Amortization of unrecognized net loss	0.3			0.3			0.5			0.5
	Total expense	$	3.5		$	3		$	7		$	5.8

Dividends_Issued

Dividends Issued	6 Months Ended
	Jun. 30, 2014
Dividends Issued [Abstract]	'
Dividends Issued	'
	Dividends Issued
	On February 11, 2014, our Board of Directors approved a dividend of $0.075 per share to the holders of record of all issued and outstanding shares of our Common Stock as of the close of business on February 24, 2014. The $2.4 million of dividends were paid to stockholders of record on March 7, 2014.
	On May 13, 2014, our Board of Directors approved a dividend of $0.075 per share to the holders of record of all issued and outstanding shares of our Common Stock as of the close of business on May 23, 2014. The $2.4 million of dividends were paid to stockholders of record on June 6, 2014.

Share_Repurchase_Program

Share Repurchase Program	6 Months Ended
	Jun. 30, 2014
Equity [Abstract]	'
Share Repurchase Program	'
	Share Repurchase Program
	On January 21, 2013, we announced that our Board of Directors had authorized the repurchase of up to $50 million of the Company's outstanding common shares through open market repurchases, negotiated block transactions or open market solicitation for shares. In 2013 we repurchased 0.6 million of our common shares for consideration of $14.1 million. We purchased an additional 0.3 million shares during the three months ended June 30, 2014 for consideration of $10.0 million. These shares are accounted for as treasury shares and the purchases were funded from our available cash balances.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Accumulated Other Comprehensive Income (Loss)	'
	Accumulated Other Comprehensive Income (Loss)
	(a) Changes in Accumulated Comprehensive Income (Loss) by Component
		Foreign				Unrealized			Pension and			Accumulated
		Currency				Gains and			Post-Retirement			Other
		Translation Loss				Losses on Cash			Obligation			Comprehensive
						Flow Hedging						Income (Loss)
						Derivatives
	Beginning Balance at January 1, 2014	$	4.1			(0.2		)	(49.1		)	(45.2		)
	Other comprehensive income (loss) before reclassifications	(3.2		)		—			0.2			(3.0		)
	Amounts reclassified from accumulated other comprehensive (income) loss	—				0.2			—			0.2
	Net current-period other comprehensive income (loss)	(3.2		)		0.2			0.2			(2.8		)
	Ending balance at June 30, 2014	$	0.9			$	—		$	(48.9	)	$	(48.0	)
	(b) Reclassifications out of Accumulated Other Comprehensive Income (Loss)
	Details about Accumulated Other Comprehensive Income (Loss) Components	Amount Reclassified from Accumulated Other Comprehensive Income (Loss)			Affected Line Item in the Statement Where Net Income is Presented
	Unrealized gains and losses on cash flow hedging derivatives	0.2			Interest expense

Earnings_Loss_Per_Share

Earnings (Loss) Per Share	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Earnings (Loss) Per Share	'
	Earnings (Loss) Per Share
	The following table sets forth the computation of basic and dilutive income (loss) per common share from continuing operations attributable to OM Group, Inc. common stockholders:
		Three Months Ended June 30					Six Months Ended June 30
		2014		2013			2014		2013
	Amounts attributable to OM Group, Inc. common stockholders:
	Income (loss) from continuing operations, net of tax	$	5.1	$	8.1		$	10.4	$	(101.2	)
	Earnings (loss) per common share - basic:
	Income (loss) from continuing operations	$	0.16	$	0.26		$	0.33	$	(3.19	)
	Earnings (loss) per common share - assuming dilution:
	Income (loss) from continuing operations	$	0.16	$	0.26		$	0.33	$	(3.19	)
	Weighted average shares outstanding — basic	31.5		31.5			31.5		31.7
	Dilutive effect of stock options and restricted stock	0.3		0.1			0.4		—
	Weighted average shares outstanding — assuming dilution	31.8		31.6			31.9		31.7
	The following table sets forth the computation of basic and diluted net income (loss) per common share attributable to OM Group, Inc. common stockholders:
		Three Months Ended June 30					Six Months Ended June 30
		2014		2013			2014		2013
	Amounts attributable to OM Group, Inc. common stockholders:
	Net income (loss)	$	4.8	$	(3.3	)	$	10.1	$	(113.1	)
	Earnings (loss) per common share - basic:
	Net income (loss)	$	0.15	$	(0.11	)	$	0.32	$	(3.57	)
	Earnings per common share - assuming dilution:
	Net income (loss)	$	0.15	$	(0.11	)	$	0.31	$	(3.57	)
	Weighted average shares outstanding — basic	31.5		31.5			31.5		31.7
	Dilutive effect of stock options and restricted stock	0.3		0.1			0.4		—
	Weighted average shares outstanding — assuming dilution	31.8		31.6			31.9		31.7
	We use the treasury stock method to calculate the effect of outstanding share-based compensation awards, which requires us to compute total employee proceeds as the sum of (a) the amount the employee must pay upon exercise of the award, (b) the amount of unearned share-based compensation costs attributed to future services and (c) the amount of tax benefits, if any, that would be credited to additional paid-in capital assuming exercise of the award. Shares, under share-based compensation awards, for which the total employee proceeds exceed the average market price over the applicable period have an anti-dilutive effect on earnings per share, and accordingly, are excluded from the calculation of diluted earnings per share.
	In the three and six months ended June 30, 2014, stock options to purchase 0.1 million and 0.1 million shares, respectively, and in the three months ended June 30, 2013 stock options to purchase 0.3 million shares of common stock were excluded from the calculation of dilutive earnings per share because the options’ exercise prices were greater than the average market price of the common shares and, therefore, the effect would have been anti-dilutive.

ShareBased_Compensation

Share-Based Compensation	6 Months Ended
	Jun. 30, 2014
Share-based Compensation [Abstract]	'
Share-Based Compensation	'
	Share-Based Compensation
	Set forth below is a summary of share-based compensation expense for option grants, restricted stock awards and restricted stock unit awards included as a component of Selling, general and administrative expenses in the Unaudited Condensed Consolidated Statements of Operations:
		Three Months Ended June 30				Six Months Ended June 30
		2014		2013		2014		2013
	Stock options and restricted stock awards	$	1.7	$	1.4	$	3.9	$	2.7
	Restricted stock unit awards	—		0.1		$	0.2	$	0.2
	Share-based compensation expense - employees	$	1.7	$	1.5	$	4.1	$	2.9
	Share-based compensation expense - non-employee directors	$	0.1	$	0.1	$	0.3	$	0.2
	No tax benefit for share-based compensation was realized during 2014 or 2013 as a result of a valuation allowance against the deferred tax assets.
	At June 30, 2014, there was $9.5 million of unrecognized compensation expense related to unvested share-based awards. That cost is expected to be recognized as follows: $3.4 million in the last six months of 2014, $4.8 million in 2015, and $1.4 million in 2016 as a component of Selling, general and administrative expenses. Unearned compensation expense is recognized over the vesting period for the particular grant. Total unrecognized compensation cost will be adjusted for future changes in actual and estimated forfeitures, updated vesting assumptions for performance awards, and fluctuations in the fair value of restricted stock unit awards.
	Non-employee directors of the Company are paid a portion of their annual retainer in unrestricted shares of common stock. For purposes of determining the number of shares of common stock to be issued, the 2007 plan provides that shares are to be valued at the average of the high and low sale price of the Company’s common stock on the New York Stock Exchange ("NYSE") on the last trading date of the quarter. Pursuant to the 2007 plan, we issued 3,976 and 7,084 shares in the three and six months ended June 30, 2014 and 5,078 and 11,049 shares in the three and six months ended June 30, 2013, respectively, to non-employee directors.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	We have potential contingent liabilities with respect to environmental matters related to our former operations in Brazil which were sold in 2003. Environmental cost-sharing arrangements are in place between the original owner and operator of these operations and between the Company and the subsequent purchaser of these operations. We have reviewed the limited information made available to us on the environmental conditions and are awaiting more detailed information from the purchaser. We cannot currently evaluate whether or not, or to what extent, we will be responsible for any remediation costs until more detailed information is received and validated.
	From time to time, we are subject to various legal and regulatory proceedings, claims and assessments that arise in the normal course of business. The ultimate resolution of such proceedings, claims and assessments is inherently unpredictable and, as a result, our estimates of liability, if any, are subject to change and actual results may materially differ from such estimates. Our estimate of any costs to be incurred as a result of these proceedings, claims and assessments are accrued when the liability is considered probable and the amount can be reasonably estimated. We believe the amount of any current potential liability with respect to legal and regulatory proceedings, claims and assessments will not have a material adverse effect upon our financial condition, results of operations, or cash flows.

Reportable_Segments

Reportable Segments	6 Months Ended
	Jun. 30, 2014
Segment Reporting Information, Profit (Loss) [Abstract]	'
Reportable Segments	'
	Reportable Segments
	We operate and report our results in four operating segments: Magnetic Technologies, Battery Technologies, Specialty Chemicals, and Advanced Materials. Intersegment transactions are generally recognized based on current market prices and are eliminated in consolidation. Corporate is comprised of general and administrative expenses not allocated to the operating segments. The following table reflects the results of our reportable segments:
			Three Months Ended June 30,						Six Months Ended June 30,
			2014			2013			2014			2013
	Net Sales
	Magnetic Technologies		$	130.9		$	128.9		$	260.1		$	266
	Battery Technologies		41			40.2			81.5			81.2
	Specialty Chemicals (a)		81.9			83.4			158.8			160.7
	Advanced Materials		43.7			26.9			58.8			113.3
	Intersegment items		—			—			—			(0.1		)
			$	297.5		$	279.4		$	559.2		$	621.1
	Operating profit (loss)
	Magnetic Technologies (b)		$	3.2		$	1.2		$	8.9		$	7.5
	Battery Technologies (b)		8.1			8.2			14.5			16.5
	Specialty Chemicals (a) (b) (c)		8.5			8.2			15.9			15.2
	Advanced Materials		(2.5		)	(0.4		)	(3.5		)	1.4
	Corporate		(7.4		)	(8.0		)	(17.4		)	(17.3		)
			$	9.9		$	9.2		$	18.4		$	23.3
	Interest expense		$	(0.6	)	$	(1.8	)	$	(1.3	)	$	(9.5	)
	Foreign exchange loss		(0.9		)	2.8			(1.2		)	0.2
	Loss on divestiture of Advanced Materials business		(0.8		)	(0.5		)	(1.0		)	(112.1		)
	Other expense, net		(0.7		)	0.3			(1.4		)	(0.3		)
	Income (loss) from continuing operations before income taxes		$	6.9		$	10		$	13.5		$	(98.4	)
	Expenditures for property, plant & equipment
	Magnetic Technologies		$	6		$	5.1		$	7.7		$	8
	Battery Technologies		0.5			0.8			1.4			1.9
	Specialty Chemicals (a)		1			2.8			1.5			5
	Advanced Materials		—			—			—			6.4
	Corporate		0.1			—			0.2			—
			$	7.6		$	8.7		$	10.8		$	21.3
	Depreciation and amortization
	Magnetic Technologies		$	11.9		$	10.7		$	23.7		$	21.5
	Battery Technologies		2.6			2.5			5.1			5
	Specialty Chemicals (a)		3.5			3.6			7.1			7.5
	Advanced Materials		—			(0.3		)	—			3.9
	Corporate		0.3			0.1			0.5			0.2
			$	18.3		$	16.6		$	36.4		$	38.1
	(a)	The June 30, 2013 results related to the UPC business are excluded from the Specialty Chemicals segment.
	(b)	The three months and six ended June 30, 2013 include costs related to cost reduction initiatives of $0.4 million and $4.2 million in Magnetic Technologies, $0.5 million and $0.7 million in Battery Technologies, and $1.1 million and $1.1 million in Specialty Chemicals, respectively.
	(c)	The three months and six ended June 30, 2014 include costs related to cost reduction initiatives of $0.4 million in Specialty Chemicals.

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Principles of Consolidation	'
	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.
New Accounting Pronouncements	'
	In July 2013, the FASB issued ASU 2013-11 Presentation of Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward exists. The update requires companies to offset a liability recorded for an unrecognized tax benefit against a related deferred tax asset of a net operating loss carryforward, a similar tax loss or a tax credit carryforward if such settlement is required or expected in the event the uncertain tax position is disallowed. The amendments are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. We adopted this guidance as of March 31, 2014 and reclassified a portion of our uncertain tax position accrual to net against the related deferred tax assets. Such adoption did not have an effect on our results of operations or financial position.

Inventories_Tables

Inventories (Tables)	6 Months Ended
	Jun. 30, 2014
Inventory, Net [Abstract]	'
Inventories	'
	Inventories consist of the following:
		June 30,		December 31,
		2014		2013
	Raw materials and supplies	$	88.1	$	83.3
	Work-in-process	115.1		122.2
	Finished goods	40.6		35.4
		$	243.8	$	240.9

Acquisitions_and_Divestitures_

Acquisitions and Divestitures (Tables)	6 Months Ended
	Jun. 30, 2014
Business Combinations [Abstract]	'
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	'
	A summary of our discontinued operations activity is as follows:
		Three Months Ended June 30						Six Months Ended June 30
		2014			2013			2014			2013
	Net Sales	$	—		$	16		$	—		$	38.5
	Loss from operations of divested business (net of tax)	$	(0.1	)	$	(1.6	)	$	(0.1	)	$	(2.1	)
	Loss on disposal of business (net of tax)	(0.2		)	(9.8		)	(0.2		)	(9.8		)
	Loss from discontinued operations (net of tax)	$	(0.3	)	$	(11.4	)	$	(0.3	)	$	(11.9	)
	Loss per share from discontinued operations (net of tax):
	Basic	$	(0.01	)	$	(0.37	)	$	(0.01	)	$	(0.38	)
	Diluted	$	(0.01	)	$	(0.37	)	$	(0.01	)	$	(0.38	)

Fair_Value_Disclosures_Tables

Fair Value Disclosures (Tables)	6 Months Ended
	Jun. 30, 2014
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]	'
Assets And Liabilities Accounted For At Fair Value On A Recurring Basis	'
	The following table shows our assets and liabilities accounted for at fair value on a recurring basis:
					Fair Value Measurements at Reporting Date Using
					Quoted Prices in	Significant Other	Significant
					Active Markets for	Observable Inputs	Unobservable Inputs
					Identical Assets
	Description		30-Jun-14		(Level 1)	(Level 2)	(Level 3)
	Liabilities:
	Contingent consideration payable		1.5		—	—	1.5
Changes in Level 3 liabilities measured at fair value on a recurring basis	'
	The following table summarizes changes in Level 3 liabilities measured at fair value on a recurring basis:
			Contingent Consideration
	Fair Value at	31-Dec-13	$	1.4
	Accretion expense		0.1
	Foreign exchange		—
	Fair Value at	30-Jun-14	$	1.5

Income_Taxes_Tables

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2014
Income Tax Disclosure [Abstract]	'
Income (Loss) From Continuing Operations Before Income Tax Expense	'
	Income (loss) from continuing operations before income tax expense consists of the following:
		Three Months Ended June 30						Six Months Ended June 30
		2014			2013			2014			2013
	United States	$	0.6		$	0.2		$	(2.3	)	$	(3.7	)
	Outside the United States	6.3			9.8			15.8			(94.7		)
	Income (loss) from continuing operations before income tax expense	$	6.9		$	10		$	13.5		$	(98.4	)
	Effective Income Tax Rate	25.8		%	18.7		%	23.3		%	(4.5		)%

Defined_Benefit_Plans_Tables

Defined Benefit Plans (Tables)	6 Months Ended
	Jun. 30, 2014
U.S. Pension Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Schedule of net benefit costs and amounts recognized in other comprehensive income (loss)	'
	Set forth below is a detail of the net periodic pension expense for the U.S. defined benefit plans:
		Three Months Ended June 30						Six Months Ended June 30
		2014			2013			2014			2013
	Service cost	$	0.3		$	0.3		$	0.6		$	0.6
	Interest cost	2.3			2.1			4.7			4.2
	Amortization of unrecognized net loss	0.1			0.2			0.2			0.4
	Expected return on plan assets	(2.6		)	(2.7		)	(5.1		)	(5.2		)
	Total expense	$	0.1		$	(0.1	)	$	0.4		$	—
Non-U.S. Pension Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Schedule of net benefit costs and amounts recognized in other comprehensive income (loss)	'
	Set forth below is a detail of the net periodic pension expense for the VAC defined benefit plans:
		Three Months Ended June 30						Six Months Ended June 30
		2014			2013			2014			2013
	Service cost	$	1.7		$	1.2		$	3.4		$	2.4
	Interest cost	1.5			1.5			3.1			2.9
	Amortization of unrecognized net loss	0.3			0.3			0.5			0.5
	Total expense	$	3.5		$	3		$	7		$	5.8

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Schedule of Accumulated Other Comprehensive Income (Loss)	'
	Changes in Accumulated Comprehensive Income (Loss) by Component
		Foreign				Unrealized			Pension and			Accumulated
		Currency				Gains and			Post-Retirement			Other
		Translation Loss				Losses on Cash			Obligation			Comprehensive
						Flow Hedging						Income (Loss)
						Derivatives
	Beginning Balance at January 1, 2014	$	4.1			(0.2		)	(49.1		)	(45.2		)
	Other comprehensive income (loss) before reclassifications	(3.2		)		—			0.2			(3.0		)
	Amounts reclassified from accumulated other comprehensive (income) loss	—				0.2			—			0.2
	Net current-period other comprehensive income (loss)	(3.2		)		0.2			0.2			(2.8		)
	Ending balance at June 30, 2014	$	0.9			$	—		$	(48.9	)	$	(48.0	)
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)	'
	Reclassifications out of Accumulated Other Comprehensive Income (Loss)
	Details about Accumulated Other Comprehensive Income (Loss) Components	Amount Reclassified from Accumulated Other Comprehensive Income (Loss)			Affected Line Item in the Statement Where Net Income is Presented
	Unrealized gains and losses on cash flow hedging derivatives	0.2			Interest expense

Earnings_Loss_Per_Share_Tables

Earnings (Loss) Per Share (Tables)	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Computation Of Basic And Diluted Income (Loss) Per Common Share From Continuing Operations	'
	The following table sets forth the computation of basic and dilutive income (loss) per common share from continuing operations attributable to OM Group, Inc. common stockholders:
		Three Months Ended June 30					Six Months Ended June 30
		2014		2013			2014		2013
	Amounts attributable to OM Group, Inc. common stockholders:
	Income (loss) from continuing operations, net of tax	$	5.1	$	8.1		$	10.4	$	(101.2	)
	Earnings (loss) per common share - basic:
	Income (loss) from continuing operations	$	0.16	$	0.26		$	0.33	$	(3.19	)
	Earnings (loss) per common share - assuming dilution:
	Income (loss) from continuing operations	$	0.16	$	0.26		$	0.33	$	(3.19	)
	Weighted average shares outstanding — basic	31.5		31.5			31.5		31.7
	Dilutive effect of stock options and restricted stock	0.3		0.1			0.4		—
	Weighted average shares outstanding — assuming dilution	31.8		31.6			31.9		31.7
Computation Of Basic And Diluted Net Income (Loss) Per Common Share	'
	The following table sets forth the computation of basic and diluted net income (loss) per common share attributable to OM Group, Inc. common stockholders:
		Three Months Ended June 30					Six Months Ended June 30
		2014		2013			2014		2013
	Amounts attributable to OM Group, Inc. common stockholders:
	Net income (loss)	$	4.8	$	(3.3	)	$	10.1	$	(113.1	)
	Earnings (loss) per common share - basic:
	Net income (loss)	$	0.15	$	(0.11	)	$	0.32	$	(3.57	)
	Earnings per common share - assuming dilution:
	Net income (loss)	$	0.15	$	(0.11	)	$	0.31	$	(3.57	)
	Weighted average shares outstanding — basic	31.5		31.5			31.5		31.7
	Dilutive effect of stock options and restricted stock	0.3		0.1			0.4		—
	Weighted average shares outstanding — assuming dilution	31.8		31.6			31.9		31.7

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2014
Share-based Compensation [Abstract]	'
Share-Based Compensation Expense For Option Grants, Restricted Stock Awards And Restricted Stock Unit Awards	'
	Set forth below is a summary of share-based compensation expense for option grants, restricted stock awards and restricted stock unit awards included as a component of Selling, general and administrative expenses in the Unaudited Condensed Consolidated Statements of Operations:
		Three Months Ended June 30				Six Months Ended June 30
		2014		2013		2014		2013
	Stock options and restricted stock awards	$	1.7	$	1.4	$	3.9	$	2.7
	Restricted stock unit awards	—		0.1		$	0.2	$	0.2
	Share-based compensation expense - employees	$	1.7	$	1.5	$	4.1	$	2.9
	Share-based compensation expense - non-employee directors	$	0.1	$	0.1	$	0.3	$	0.2

Reportable_Segments_Tables

Reportable Segments (Tables)	6 Months Ended
	Jun. 30, 2014
Segment Reporting Information, Profit (Loss) [Abstract]	'
Results of reportable segments	'
	The following table reflects the results of our reportable segments:
			Three Months Ended June 30,						Six Months Ended June 30,
			2014			2013			2014			2013
	Net Sales
	Magnetic Technologies		$	130.9		$	128.9		$	260.1		$	266
	Battery Technologies		41			40.2			81.5			81.2
	Specialty Chemicals (a)		81.9			83.4			158.8			160.7
	Advanced Materials		43.7			26.9			58.8			113.3
	Intersegment items		—			—			—			(0.1		)
			$	297.5		$	279.4		$	559.2		$	621.1
	Operating profit (loss)
	Magnetic Technologies (b)		$	3.2		$	1.2		$	8.9		$	7.5
	Battery Technologies (b)		8.1			8.2			14.5			16.5
	Specialty Chemicals (a) (b) (c)		8.5			8.2			15.9			15.2
	Advanced Materials		(2.5		)	(0.4		)	(3.5		)	1.4
	Corporate		(7.4		)	(8.0		)	(17.4		)	(17.3		)
			$	9.9		$	9.2		$	18.4		$	23.3
	Interest expense		$	(0.6	)	$	(1.8	)	$	(1.3	)	$	(9.5	)
	Foreign exchange loss		(0.9		)	2.8			(1.2		)	0.2
	Loss on divestiture of Advanced Materials business		(0.8		)	(0.5		)	(1.0		)	(112.1		)
	Other expense, net		(0.7		)	0.3			(1.4		)	(0.3		)
	Income (loss) from continuing operations before income taxes		$	6.9		$	10		$	13.5		$	(98.4	)
	Expenditures for property, plant & equipment
	Magnetic Technologies		$	6		$	5.1		$	7.7		$	8
	Battery Technologies		0.5			0.8			1.4			1.9
	Specialty Chemicals (a)		1			2.8			1.5			5
	Advanced Materials		—			—			—			6.4
	Corporate		0.1			—			0.2			—
			$	7.6		$	8.7		$	10.8		$	21.3
	Depreciation and amortization
	Magnetic Technologies		$	11.9		$	10.7		$	23.7		$	21.5
	Battery Technologies		2.6			2.5			5.1			5
	Specialty Chemicals (a)		3.5			3.6			7.1			7.5
	Advanced Materials		—			(0.3		)	—			3.9
	Corporate		0.3			0.1			0.5			0.2
			$	18.3		$	16.6		$	36.4		$	38.1
	(a)	The June 30, 2013 results related to the UPC business are excluded from the Specialty Chemicals segment.
	(b)	The three months and six ended June 30, 2013 include costs related to cost reduction initiatives of $0.4 million and $4.2 million in Magnetic Technologies, $0.5 million and $0.7 million in Battery Technologies, and $1.1 million and $1.1 million in Specialty Chemicals, respectively.
	(c)	The three months and six ended June 30, 2014 include costs related to cost reduction initiatives of $0.4 million in Specialty Chemicals.

Basis_of_Presentation_Narrativ

Basis of Presentation (Narrative) (Details)	Mar. 29, 2013
Accounting Policies [Abstract]	'
Percentage of interest in joint venture by the company	55.00%
Noncontrolling interest in joint venture	45.00%

Inventories_Inventories_Detail

Inventories (Inventories) (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Inventory, Net [Abstract]	'	'
Raw materials and supplies	$88.10	$83.30
Work-in-process	115.1	122.2
Finished goods	40.6	35.4
Inventories, total	$243.80	$240.90

Acquisitions_and_Divestitures_1

Acquisitions and Divestitures (Narrative) (Details) (USD $)

3 Months Ended

6 Months Ended

0 Months Ended

1 Months Ended

3 Months Ended

6 Months Ended

0 Months Ended

3 Months Ended

6 Months Ended

1 Months Ended

In Millions, unless otherwise specified

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Mar. 29, 2013

Jul. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2013

Mar. 29, 2013

Mar. 29, 2013

31-May-13

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Aug. 31, 2013

Aug. 02, 2011

Advanced Materials [Member]

Advanced Materials [Member]

Advanced Materials [Member]

Advanced Materials [Member]

Advanced Materials [Member]

Advanced Materials [Member]

Advanced Materials [Member]

Ultra Pure Chemicals [Member]

Ultra Pure Chemicals [Member]

Ultra Pure Chemicals [Member]

Ultra Pure Chemicals [Member]

Ultra Pure Chemicals [Member]

VAC [Member]

VAC [Member]

Mg

Maximum [Member]

Minimum [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase price total cash consideration

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$812.20

Cash consideration paid for business acquisition

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

686.2

'

Purchase price of VAC Holding payable to seller

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

86.3

Shares issued in connection with acquisition of VAC Holding

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

39.7

Business Combination, Period from Closing Date of Acquisition with Certain Exceptions Related to Tax Matters

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2 years

'

Payments for Purchase Price Payable to Seller

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

23

'

Agreed Upon Proceeds From Divestiture From Business Subject To Close

'

'

'

'

329

'

'

'

'

'

'

'

'

'

'

'

'

'

Net proceeds from divestiture of Advanced Materials Business

'

'

'

'

302

'

'

0

302.1

'

'

'

'

'

'

'

'

'

Net proceeds from divestiture of Advanced Materials business

'

'

'

'

'

27

'

'

'

'

'

63

'

'

'

'

'

'

Loss on divestiture of Advanced Materials business

-0.8

-0.5

-1

-112.1

-112

'

'

'

'

'

'

'

'

'

'

'

'

'

Write-off of deferred financing fees

'

'

'

'

10

'

'

'

'

'

'

1.5

'

'

'

'

'

'

Disposal Group, Including Discontinued Operation, Provision for Doubtful Accounts

'

'

'

'

16

'

'

'

'

'

'

'

'

'

'

'

'

'

Disposal Group, Including Discontinued Operation, Transaction Expense

'

'

'

'

9

'

'

'

'

'

'

1

'

'

'

'

'

'

Disposal Group, Including Discontinued Operation, Other Expense

'

'

'

'

'

'

0.8

'

'

'

'

'

'

'

'

'

'

'

Disposal Group, Potential Earn-Out Income

'

'

'

'

'

'

'

'

'

110

'

'

'

'

'

'

'

'

Disposal Group, Potential Earn-Out Payment Period

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

Supply Agreement Period

'

'

'

'

'

'

'

'

'

'

'2 years

'

'

'

'

'

'

'

Cobalt Feed Supply Agreement, Quantity

'

'

'

'

7,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Supply Agreement Extension Period

'

'

'

'

'6 months

'

'

'

'

'

'

'

'

'

'

'

'

'

Working capital adjustment

'

'

'

'

'

'

'

'

'

'

'

3

'

'

'

'

'

'

Loss divestiture

'

'

'

'

'

'

'

'

'

'

'

9.8

-0.2

-9.8

-0.2

-9.8

'

'

Disposal Group, Including Discontinued Operations, Gain on Sale of Net Assets

'

'

'

'

'

'

'

'

'

'

'

1.5

0.2

'

'

'

'

'

Reclassification of foreign currency translation adjustment related to the discontinued operations into earnings

0

8.8

0

8.8

'

'

'

'

'

'

'

-8.8

'

'

'

'

'

'

Discontinued Operations, Interest Expense, Debt Repaid by Proceeds From Divestiture of Business

'

'

'

'

'

'

'

'

'

'

'

$1

'

'

'

'

'

'

Acquisitions_and_Divestitures_2

Acquisitions and Divestitures (Income Statement Impact Discontinued Operations) (Details) (USD $)	0 Months Ended	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	31-May-13	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'	'
Loss from discontinued operations (net of tax)	'	($0.30)	($11.40)	($0.30)	($11.90)
Loss per share from discontinued operations -- Basic (net of tax) (in dollars per share)	'	($0.01)	($0.37)	($0.01)	($0.38)
Loss per share from discontinued operations -- Diluted (net of tax) (in dollars per share)	'	($0.01)	($0.37)	($0.02)	($0.38)
Ultra Pure Chemicals [Member]	'	'	'	'	'
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'	'
Disposal Group, Including Discontinued Operations, Gain on Sale of Net Assets	1.5	0.2	'	'	'
Net Sales	'	0	16	0	38.5
Loss from operations of divested business (net of tax)	'	-0.1	-1.6	-0.1	-2.1
Loss on disposal of business (net of tax)	9.8	-0.2	-9.8	-0.2	-9.8
Loss from discontinued operations (net of tax)	'	($0.30)	($11.40)	($0.30)	($11.90)
Loss per share from discontinued operations -- Basic (net of tax) (in dollars per share)	'	($0.01)	($0.37)	($0.01)	($0.38)
Loss per share from discontinued operations -- Diluted (net of tax) (in dollars per share)	'	($0.01)	($0.37)	($0.01)	($0.38)

Debt_Details

Debt (Details) (USD $)	Jun. 30, 2014	Sep. 04, 2013	Sep. 04, 2013	Sep. 04, 2013	Sep. 04, 2013	Sep. 04, 2013	Sep. 04, 2013	Sep. 04, 2013
		Senior Secured Revolving Credit New Facility [Member]	Senior Secured Revolving Credit New Facility [Member]	Senior Secured Revolving Credit New Facility [Member]	Senior Secured Revolving Credit New Facility [Member]	Senior Secured Revolving Credit New Facility [Member]	Senior Secured Revolving Credit New Facility [Member]	Senior Secured Revolving Credit New Facility [Member]
			Federal Funds Rate [Member]	London Interbank Offered Rate (LIBOR) [Member]	London Interbank Offered Rate (LIBOR) [Member]	London Interbank Offered Rate (LIBOR) [Member]	Applicable Margin [Member]	Applicable Margin [Member]
			Adjusted Base Rate Advances [Member]	Adjusted Base Rate Advances [Member]	Minimum [Member]	Maximum [Member]	Minimum [Member]	Maximum [Member]
					Variable Spread [Member]	Variable Spread [Member]	Adjusted Base Rate Advances [Member]	Adjusted Base Rate Advances [Member]
Line of Credit Facility [Line Items]	'	'	'	'	'	'	'	'
Debt Instrument, Term	'	'5 years	'	'	'	'	'	'
Undrawn revolving credit facility	'	$350,000,000	'	'	'	'	'	'
Line of Credit Facility, Borrowing Capacity Increase Limit	'	150,000,000	'	'	'	'	'	'
Debt Instrument, Percentage Pledged by Voting Capital Stock of Certain Foreign Subsidiaries	'	65.00%	'	'	'	'	'	'
Percentage Of Pledge Of Voting Capital Stock Subject To Certain Exceptions	'	100.00%	'	'	'	'	'	'
Debt Instrument, Basis Spread on Variable Rate	'	'	0.50%	1.00%	1.13%	2.00%	0.13%	1.00%
Line of Credit Facility, Amount Outstanding	$0	'	'	'	'	'	'	'

Derivative_Instruments_Narrati

Derivative Instruments (Narrative) (Details) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2013
		Interest Rate Swap Agreements [Member]	Interest Rate Swap Agreements [Member]
Derivatives, Fair Value [Line Items]	'	'	'
Notional amount of derivatives	'	'	$114,500,000
Hedge ineffectiveness recorded to income	$0	$0	'

Fair_Value_Disclosures_Details

Fair Value Disclosures (Details)	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014
	USD ($)	Rahu Catalytics Limited [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Volume Targets [Member]	Volume Targets [Member]
			Contingent Consideration [Member]	Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]	Significant Other Observable Inputs (Level 2) [Member]	Significant Unobservable Inputs (Level 3) [Member]	Rahu Catalytics Limited [Member]	Rahu Catalytics Limited [Member]
			USD ($)	Contingent Consideration [Member]	Contingent Consideration [Member]	Contingent Consideration [Member]	USD ($)	EUR (€)
				USD ($)	USD ($)	USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]	'	'	'	'	'	'	'	'
Fair value measurements, total liabilities	'	'	$1,500,000	$0	$0	$1,500,000	'	'
Transfer into or out of fair value measurement	0	'	'	'	'	'	'	'
Contingent consideration amounts based on certain volume targets	'	'	'	'	'	'	$27,300,000	€ 20,000,000
Business combination, contingent consideration based on achieving target volumes	'	'15 years	'	'	'	'	'	'

Fair_Value_Disclosures_Changes

Fair Value Disclosures (Changes in Level 3 liabilities measured at fair value on a recurring basis) (Details) (Significant Unobservable Inputs (Level 3) [Member], USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014
Significant Unobservable Inputs (Level 3) [Member]	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Fair Value at December 31, 2013	$1.40
Accretion expense	0.1
Foreign exchange	0
Fair Value at June 30, 2014	$1.50

Income_Taxes_Income_Loss_From_

Income Taxes (Income (Loss) From Continuing Operations Before Income Tax Expense) (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income (loss) from continuing operations before income tax expense:	'	'	'	'
United States	$0.60	$0.20	($2.30)	($3.70)
Outside the United States	6.3	9.8	15.8	-94.7
Income (loss) from continuing operations before income tax expense	$6.90	$10	$13.50	($98.40)
Effective Income Tax Rate	25.80%	18.70%	23.30%	-4.50%

Defined_Benefit_Plans_Narrativ

Defined Benefit Plans (Narrative) (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension liabilities	$218.40	$220.50
VAC [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Pension liabilities	$227.90	$230

Defined_Benefit_Plans_Schedule

Defined Benefit Plans (Schedule of Net Benefit Costs and Amounts Recognized in Other Comprehensive Income (Loss)) (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
U.S. Pension Plans [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Service cost	$0.30	$0.30	$0.60	$0.60
Interest cost	2.3	2.1	4.7	4.2
Amortization of unrecognized net loss	0.1	0.2	0.2	0.4
Expected return on plan assets	-2.6	-2.7	-5.1	-5.2
Total expense	0.1	-0.1	0.4	0
Non-U.S. Pension Plans [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Service cost	1.7	1.2	3.4	2.4
Interest cost	1.5	1.5	3.1	2.9
Amortization of unrecognized net loss	0.3	0.3	0.5	0.5
Total expense	$3.50	$3	$7	$5.80

Dividends_Issued_Details

Dividends Issued (Details) (USD $)	0 Months Ended				3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 06, 2014	13-May-14	Mar. 07, 2014	Feb. 11, 2014	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Dividends Issued [Abstract]	'	'	'	'	'	'	'	'
Dividends declared per common share (in dollars per share)	'	$0.08	'	$0.08	$0.08	$0	$0.15	$0
Dividends paid	$2.40	'	$2.40	'	'	'	$4.80	$0

Share_Repurchase_Program_Detai

Share Repurchase Program (Details) (USD $)	3 Months Ended	12 Months Ended
Share data in Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jan. 21, 2013
Equity [Abstract]	'	'	'
Stock Repurchase Program, Authorized Amount	'	'	$50,000,000
Treasury Stock, Shares, Acquired	0.3	0.6	'
Treasury Stock, Value, Acquired, Cost Method	$10,000,000	$14,100,000	'

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning Balance at January 1, 2014	'	'	($45.20)	'
Other comprehensive income (loss) before reclassifications	'	'	-3	'
Amounts reclassified from accumulated other comprehensive (income) loss	'	'	0.2	'
Net change in accumulated other comprehensive income	-1.1	18.3	-2.8	-7
Ending balance at June 30, 2014	-48	'	-48	'
Foreign Currency Translation Loss	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning Balance at January 1, 2014	'	'	4.1	'
Other comprehensive income (loss) before reclassifications	'	'	-3.2	'
Amounts reclassified from accumulated other comprehensive (income) loss	'	'	0	'
Net change in accumulated other comprehensive income	'	'	-3.2	'
Ending balance at June 30, 2014	0.9	'	0.9	'
Foreign Currency Translation Loss | Reclassification out of Accumulated Other Comprehensive Income	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Unrealized gains and losses on cash flow hedging derivatives	'	'	0.2	'
Unrealized Gains and Losses on Cash Flow Hedging Derivatives	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning Balance at January 1, 2014	'	'	-0.2	'
Other comprehensive income (loss) before reclassifications	'	'	0	'
Amounts reclassified from accumulated other comprehensive (income) loss	'	'	0.2	'
Net change in accumulated other comprehensive income	'	'	0.2	'
Ending balance at June 30, 2014	0	'	0	'
Pension and Post-Retirement Obligation	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'	'	'	'
Beginning Balance at January 1, 2014	'	'	-49.1	'
Other comprehensive income (loss) before reclassifications	'	'	0.2	'
Amounts reclassified from accumulated other comprehensive (income) loss	'	'	0	'
Net change in accumulated other comprehensive income	'	'	0.2	'
Ending balance at June 30, 2014	($48.90)	'	($48.90)	'

Earnings_Loss_Per_Share_Comput

Earnings (Loss) Per Share (Computation Of Basic And Diluted Income Per Common Share From Continuing Operations) (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Income (loss) from continuing operations, net of tax	$5.10	$8.10	$10.40	($101.20)
Earnings per common share:	'	'	'	'
Income (loss) from continuing operations attributable to OM Group, Inc. common stockholders - basic (in dollars per share)	$0.16	$0.26	$0.33	($3.19)
Income (loss) from continuing operations attributable to OM Group, Inc. common stockholders - assuming dilution (in dollars per share)	$0.16	$0.26	$0.33	($3.19)
Weighted average shares outstanding - basic (in shares)	31.5	31.5	31.5	31.7
Dilutive effect of stock options and restricted stock (in shares)	0.3	0.1	0.4	0
Weighted average shares outstanding - assuming dilution (in shares)	31.8	31.6	31.9	31.7

Earnings_Loss_Per_Share_Comput1

Earnings (Loss) Per Share (Computation Of Basic And Diluted Net Income Per Common Share) (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net income (loss) attributable to OM Group, Inc. common stockholders	$4.80	($3.30)	$10.10	($113.10)
Earnings per common share:	'	'	'	'
Net income (loss) attributable to OM Group, Inc. common stockholders - basic (in dollars per share)	$0.15	($0.11)	$0.32	($3.57)
Net income (loss) attributable to OM Group, Inc. common stockholders - assuming dilution (in dollars per share)	$0.15	($0.11)	$0.31	($3.57)
Weighted average shares outstanding - basic (in shares)	31.5	31.5	31.5	31.7
Dilutive effect of stock options and restricted stock (in shares)	0.3	0.1	0.4	0
Weighted average shares outstanding - assuming dilution (in shares)	31.8	31.6	31.9	31.7

Earnings_Loss_Per_Share_NonVes

Earnings (Loss) Per Share (Non-Vested Share-Based Compensation Awards That Could Potentially Dilute Earnings Per Share) (Details)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014
Earnings Per Share [Abstract]	'	'	'
Non-vested share-based compensation awards not included in the fully diluted computation (in shares)	0.1	0.3	0.1

ShareBased_Compensation_Narrat

Share-Based Compensation (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	'	'	0	0
Director [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Share-based Goods and Nonemployee Services Transaction, Quantity of Securities Issued	3,976	5,078	7,084	11,049

ShareBased_Compensation_Compen

Share-Based Compensation (Compensation Expense For Option Grants, Restricted Stock Awards And Restricted Stock Unit Awards) (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Employees [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Share-based compensation expense	$1.70	$1.50	$4.10	$2.90
Stock Options and Restricted Stock Awards [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Share-based compensation expense	1.7	1.4	3.9	2.7
Restricted Stock Unit Awards [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Share-based compensation expense	0	0.1	0.2	0.2
Director [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Share-based compensation expense	$0.10	$0.10	$0.30	$0.20

ShareBased_Compensation_Compen1

Share-Based Compensation (Compensation Expense For Nonvested Share-Based Awards Expected To Be Recognized) (Details) (USD $)	Jun. 30, 2014
In Millions, unless otherwise specified
Share-based Compensation [Abstract]	'
Unrecognized compensation expense	$9.50
Unrecognized compensation expense to be recognized in 2014	3.4
Unrecognized compensation expense to be recognized in 2015	4.8
Unrecognized compensation expense to be recognized in 2016	$1.40

Reportable_Segments_Results_of

Reportable Segments (Results of Reportable Segments) (Details) (USD $)

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

0 Months Ended

In Millions, unless otherwise specified

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Mar. 29, 2013

Magnetic Technologies [Member]

Magnetic Technologies [Member]

Magnetic Technologies [Member]

Magnetic Technologies [Member]

Battery Technologies [Member]

Battery Technologies [Member]

Battery Technologies [Member]

Battery Technologies [Member]

Specialty Chemicals [Member]

Specialty Chemicals [Member]

Specialty Chemicals [Member]

Specialty Chemicals [Member]

Advanced Materials [Member]

Advanced Materials [Member]

Advanced Materials [Member]

Advanced Materials [Member]

Corporate [Member]

Corporate [Member]

Corporate [Member]

Corporate [Member]

Intersegment items [Member]

Intersegment items [Member]

Intersegment items [Member]

Intersegment items [Member]

Advanced Materials [Member]

Net Sales

'

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Net sales

$297.50

$279.40

$559.20

$621.10

$130.90

$128.90

$260.10

$266

$41

$40.20

$81.50

$81.20

$81.90

[1]

$83.40

[1]

$158.80

[1]

$160.70

[1]

$43.70

$26.90

$58.80

$113.30

'

'

'

'

$0

$0

$0

($0.10)

'

Operating profit (loss)

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating profit (loss)

9.9

9.2

18.4

23.3

3.2

[2]

1.2

[2]

8.9

[2]

7.5

[2]

8.1

[2]

8.2

[2]

14.5

[2]

16.5

[2]

8.5

[1],[2],[3]

8.2

[1],[2],[3]

15.9

[1],[2],[3]

15.2

[1],[2],[3]

-2.5

-0.4

-3.5

1.4

-7.4

-8

-17.4

-17.3

'

'

'

'

'

Interest expense

-0.6

-1.8

-1.3

-9.5

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'

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'

'

'

'

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'

'

'

'

'

'

'

'

Foreign exchange loss

-0.9

2.8

-1.2

0.2

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'

'

'

'

'

Loss on divestiture of Advanced Materials business

-0.8

-0.5

-1

-112.1

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'

'

'

-112

Other expense, net

-0.7

0.3

-1.4

-0.3

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'

'

Income (loss) from continuing operations before income tax expense

6.9

10

13.5

-98.4

'

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'

'

'

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'

'

Expenditures for property, plant & equipment

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

Expenditures for property, plant and equipment

7.6

8.7

10.8

21.3

6

5.1

7.7

8

0.5

0.8

1.4

1.9

1

[1]

2.8

[1]

1.5

[1]

5

[1]

0

0

0

6.4

0.1

0

0.2

0

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'

'

Depreciation and amortization

'

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Depreciation and amortization

18.3

16.6

36.4

38.1

11.9

10.7

23.7

21.5

2.6

2.5

5.1

5

3.5

[1]

3.6

[1]

7.1

[1]

7.5

[1]

0

-0.3

0

3.9

0.3

0.1

0.5

0.2

'

'

'

'

'

Cost Reductions Initiatives

'

'

'

'

'

$0.40

'

$4.20

'

$0.50

'

$0.70

$0.40

$1.10

'

$1.10

'

'

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'

'

'

'

'

'

'

'

'

'

[1]

The June 30, 2013 results related to the UPC business are excluded from the Specialty Chemicals segment.

[2]

The three months and six ended June 30, 2013 include costs related to cost reduction initiatives of $0.4 million and $4.2 million in Magnetic Technologies, $0.5 million and $0.7 million in Battery Technologies, and $1.1 million and $1.1 million in Specialty Chemicals, respectively.

[3]

The three months and six ended June 30, 2014 include costs related to cost reduction initiatives of $0.4 million in Specialty Chemicals.