Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2011

Earnings Per Share [Abstract]

Computation Of Basic And Diluted Income Per Common Share From Continuing Operations

	Three Months Ended September 30,					Nine Months Ended September 30,
	2011			2010		2011			2010
Income (loss) from continuing operations attributable to OM Group, Inc. common stockholders	$	(68,488	)	$	23,198	$	(12,887	)	$	58,968
Weighted average shares outstanding — basic		31,382			30,474		30,817			30,417
Dilutive effect of stock options and restricted stock		—			86		—			118
Weighted average shares outstanding — assuming dilution		31,382			30,560		30,817			30,535
Earnings per common share:
Income (loss) from continuing operations attributable to OM Group, Inc. common stockholders — basic	$	(2.18	)	$	0.76	$	(0.42	)	$	1.94
Income (loss) from continuing operations attributable to OM Group, Inc. common stockholders — assuming dilution	$	(2.18	)	$	0.76	$	(0.42	)	$	1.93

Computation Of Basic And Diluted Net Income Per Common Share

	Three Months Ended September 30,					Nine Months Ended September 30,
	2011			2010		2011			2010
Net income (loss) attributable to OM Group, Inc. common stockholders	$	(68,254	)	$	24,201	$	(12,982	)	$	59,590
Weighted average shares outstanding — basic		31,382			30,474		30,817			30,417
Dilutive effect of stock options and restricted stock		—			86		—			118
Weighted average shares outstanding — assuming dilution		31,382			30,560		30,817			30,535
Earnings per common share:
Net income (loss) attributable to OM Group, Inc. common stockholders — basic	$	(2.17	)	$	0.79	$	(0.42	)	$	1.96
Net income (loss) attributable to OM Group, Inc. common stockholders — assuming dilution	$	(2.17	)	$	0.79	$	(0.42	)	$	1.95

Non-Vested Share-Based Compensation Awards That Could Potentially Dilute Earnings Per Share

2011	2010	2011	2010
—	301	—	220