Earnings Per Share

12 Months Ended

Dec. 31, 2011

Earnings Per Share [Abstract]

Earnings Per Share

Earnings 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 for the years ended December 31:

	2011		2010		2009
	(in thousands, except per share amounts)
Income (loss) from continuing operations attributable to
OM Group, Inc. common stockholders	$	37,961	$	82,648	$	(19,353	)
Weighted average shares outstanding — basic	31,079		30,433		30,244
Dilutive effect of stock options and restricted stock	165		132		—
Weighted average shares outstanding — assuming dilution	31,244		30,565		30,244
Earnings per common share:
Income (loss) from continuing operations attributable to
OM Group, Inc. common stockholders — basic	$	1.22	$	2.72	$	(0.64	)
Income (loss) from continuing operations attributable to
OM Group, Inc. common stockholders — assuming dilution	$	1.21	$	2.70	$	(0.64	)

The following table sets forth the computation of basic and diluted net income (loss) per common share attributable to OM Group, Inc. common stockholders for the years ended December 31:

	2011		2010		2009
	(in thousands, except per share amounts)
Net income (loss) attributable to OM Group, Inc. common stockholders	$	37,902	$	83,374	$	(17,857	)
Weighted average shares outstanding — basic	31,079		30,433		30,244
Dilutive effect of stock options and restricted stock	165		132		—
Weighted average shares outstanding — assuming dilution	31,244		30,565		30,244
Earnings per common share:
Net income (loss) attributable to OM Group, Inc. common stockholders — basic	$	1.22	$	2.74	$	(0.59	)
Net income (loss) attributable to OM Group, Inc. common stockholders — assuming dilution	$	1.21	$	2.73	$	(0.59	)

The Company uses the treasury stock method to calculate the effect of outstanding share-based compensation awards, which requires the Company 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 antidilutive effect on earnings per share, and accordingly, are excluded from the calculation of diluted earnings per share.

In the years ended December 31, 2011 and 2010, stock options to purchase 0.2 million shares and 0.2 million shares, respectively, 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. As the Company had a loss from continuing operations for the year ended December 31, 2009, the effect of including dilutive securities in the earnings per share calculation would have been anti-dilutive. Accordingly, all shares under share-based compensation awards were excluded from the calculation of loss from continuing operations attributable to OM Group, Inc. common stockholders assuming dilution and net loss attributable to OM Group, Inc. common stockholders assuming dilution for the year ended December 31, 2009.