Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2013

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 (loss) per common share from continuing operations attributable to OM Group, Inc. common stockholders:

	Three Months Ended June 30					Six Months Ended June 30
Amounts attributable to OM Group, Inc. common stockholders:	2013		2012			2013			2012
(in thousands, except per share amounts)
Income (loss) from continuing operations, net of tax	$	8,068	$	(22,753	)	$	(101,170	)	$	(10,685	)
Earnings (loss) per common share - basic:
Income (loss) from continuing operations	$	0.26	$	(0.71	)	$	(3.19	)	$	(0.34	)
Earnings (loss) per common share - assuming dilution:
Income (loss) from continuing operations	$	0.26	$	(0.71	)	$	(3.19	)	$	(0.34	)
Weighted average shares outstanding — basic	31,452		31,882			31,673			31,878
Dilutive effect of stock options and restricted stock	169		—			—			—
Weighted average shares outstanding — assuming dilution	31,621		31,882			31,673			31,878

Computation Of Basic And Diluted Net Income Per Common Share

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

	Three Months Ended June 30						Six Months Ended June 30
Amounts attributable to OM Group, Inc. common stockholders:	2013			2012			2013			2012
(in thousands, except per share amounts)
Net income (loss)	$	(3,326	)	$	(22,339	)	$	(113,040	)	$	(10,390	)
Earnings (loss) per common share - basic:
Net income (loss)	$	(0.11	)	$	(0.70	)	$	(3.57	)	$	(0.33	)
Earnings per common share - assuming dilution:
Net income (loss)	$	(0.11	)	$	(0.70	)	$	(3.57	)	$	(0.33	)
Weighted average shares outstanding — basic	31,452			31,882			31,673			31,878
Dilutive effect of stock options and restricted stock	169			—			—			—
Weighted average shares outstanding — assuming dilution	31,621			31,882			31,673			31,878