Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2012

Earnings Per Share [Abstract]

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

The following table sets forth the computation of basic and dilutive income per common share from continuing operations attributable to OM Group, Inc. common stockholders:

	Three Months Ended					Nine Months Ended
	September 30,					September 30,
	2012		2011			2012			2011
(in thousands, except per share amounts)
Amounts attributable to OM Group, Inc. common stockholders:
Income (loss) from continuing operations, net of tax	$	5,656	$	(68,488	)	$	(4,772	)	$	(12,887	)
Earnings per common share — basic:
Income (loss) from continuing operations attributable to OM Group, Inc. common stockholders	$	0.18	$	(2.18	)	$	(0.15	)	$	(0.42	)
Earnings per common share — assuming dilution:
Income (loss) from continuing operations attributable to OM Group, Inc. common stockholders	$	0.18	$	(2.18	)	$	(0.15	)	$	(0.42	)
Weighted average shares outstanding — basic	31,889		31,382			31,882			30,817
Dilutive effect of stock options and restricted stock	115		—			—			—
Weighted average shares outstanding — assuming dilution	32,004		31,382			31,882			30,817

Computation Of Basic And Diluted Net Income Per Common Share

The following table sets forth the computation of basic and diluted net income per common share attributable to OM Group, Inc. common stockholders:

	Three Months Ended					Nine Months Ended
	September 30,					September 30,
	2012		2011			2012			2011
(in thousands, except per share amounts)
Amounts attributable to OM Group, Inc. common stockholders:
Net income (loss)	$	5,508	$	(68,254	)	$	(4,882	)	$	(12,982	)
Earnings per common share — basic:
Net income (loss) attributable to OM Group, Inc. common stockholders	$	0.17	$	(2.17	)	$	(0.15	)	$	(0.42	)
Earnings per common share — assuming dilution:
Net income (loss) attributable to OM Group, Inc. common stockholders	$	0.17	$	(2.17	)	$	(0.15	)	$	(0.42	)
Weighted average shares outstanding — basic	31,889		31,382			31,882			30,817
Dilutive effect of stock options and restricted stock	115		—			—			—
Weighted average shares outstanding — assuming dilution	32,004		31,382			31,882			30,817