Earnings Per Share (Tables)

6 Months Ended

Jun. 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					Six Months Ended
	June 30,					June 30,
	2012			2011		2012			2011
(in thousands, except per share amounts)
Income (loss) from continuing operations attributable to
OM Group, Inc. common stockholders	$	(22,513	)	$	24,709	$	(10,428	)	$	55,601
Weighted average shares outstanding — basic	31,882			30,535		31,878			30,531
Dilutive effect of stock options and restricted stock	—			186		—			177
Weighted average shares outstanding — assuming dilution	31,882			30,721		31,878			30,708
Earnings per common share:
Income (loss) from continuing operations attributable to
OM Group, Inc. common stockholders — basic	$	(0.71	)	$	0.81	$	(0.33	)	$	1.82
Income (loss) from continuing operations attributable to
OM Group, Inc. common stockholders — assuming dilution	$	(0.71	)	$	0.80	$	(0.33	)	$	1.81

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					Six Months Ended
	June 30,					June 30,
	2012			2011		2012			2011
(in thousands, except per share amounts)
Net income (loss) attributable to OM Group, Inc. common stockholders	$	(22,339	)	$	24,620	$	(10,390	)	$	55,272
Weighted average shares outstanding — basic	31,882			30,535		31,878			30,531
Dilutive effect of stock options and restricted stock	—			186		—			177
Weighted average shares outstanding — assuming dilution	31,882			30,721		31,878			30,708
Earnings per common share:
Net income (loss) attributable to OM Group, Inc. common stockholders — basic	$	(0.70	)	$	0.81	$	(0.33	)	$	1.81
Net income (loss) attributable to OM Group, Inc. common stockholders — assuming dilution	$	(0.70	)	$	0.80	$	(0.33	)	$	1.80