Unaudited Condensed Statements of Consolidated Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Income Statement [Abstract]
Net sales	$ 436,467	$ 329,522	$ 902,646	$ 660,867
Cost of goods sold	393,329	256,016	760,198	505,323
Gross profit	43,138	73,506	142,448	155,544
Selling, general and administrative expenses	65,301	45,489	130,175	89,767
Operating profit (loss)	(22,163)	28,017	12,273	65,777
Other income (expense):
Interest expense	(11,828)	(1,393)	(24,040)	(2,815)
Interest income	186	467	338	687
Foreign exchange gain (loss)	5,861	(636)	840	(161)
Other, net	(357)	(324)	(648)	(329)
Non operating income (expense), total	(6,138)	(1,886)	(23,510)	(2,618)
Income (loss) from continuing operations before income tax (expense) benefit	(28,301)	26,131	(11,237)	63,159
Income tax (expense) benefit	5,544	(330)	464	(6,076)
Income (loss) from continuing operations, net of tax	(22,757)	25,801	(10,773)	57,083
(Income) loss from discontinued operations, net of tax	174	(89)	38	(329)
Consolidated net income (loss)	(22,583)	25,712	(10,735)	56,754
Net (income) loss attributable to the noncontrolling interests	244	(1,092)	345	(1,482)
Net income (loss) attributable to OM Group, Inc. common stockholders	(22,339)	24,620	(10,390)	55,272
Earnings per common share - basic:
Income (loss) from continuing operations attributable to OM Group, Inc. common stockholders (in dollars per share)	$ (0.71)	$ 0.81	$ (0.33)	$ 1.82
Income (loss) from discontinued operations attributable to OM Group, Inc. common stockholders (in dollars per share)	$ 0.01	$ 0.00	$ 0.00	$ (0.01)
Net income (loss) attributable to OM Group, Inc. common stockholders (in dollars per share)	$ (0.70)	$ 0.81	$ (0.33)	$ 1.81
Earnings per common share - assuming dilution:
Income (loss) from continuing operations attributable to OM Group, Inc. common stockholders (in dollars per share)	$ (0.71)	$ 0.80	$ (0.33)	$ 1.81
Income (loss) from discontinued operations attributable to OM Group, Inc. common stockholders (per share)	$ 0.01	$ 0.00	$ 0.00	$ (0.01)
Net income (loss) attributable to OM Group, Inc. common stockholders (in dollars per share)	$ (0.70)	$ 0.80	$ (0.33)	$ 1.80
Weighted average shares outstanding
Basic (in shares)	31,882	30,535	31,878	30,531
Assuming dilution (in shares)	31,882	30,721	31,878	30,708
Amounts attributable to OM Group, Inc. common shareholders:
Income (loss) from continuing operations, net of tax	(22,513)	24,709	(10,428)	55,601
Income (loss) from discontinued operations, net of tax	174	(89)	38	(329)
Net income (loss) attributable to OM Group, Inc. common stockholders	$ (22,339)	$ 24,620	$ (10,390)	$ 55,272