Earnings Per Common Share (Tables)

6 Months Ended

Jun. 30, 2013

Earnings Per Share [Abstract]

Schedule of Basic and Diluted Earnings Per Common Share

The following table sets forth the computation of basic and diluted earnings per common share:

	Three Months Ended June 30,						Six Months Ended June 30,
	2013			2012			2013		2012
(Dollars in millions, except share amounts, in thousands, and per share amounts)
Net income attributable to Koppers	$	14.4		$	20.4		$	25.4	$	36.0
Less: loss from discontinued operations		(0.1	)		(0.2	)		0.0		(0.1	)
Income from continuing operations attributable to Koppers	$	14.5		$	20.6		$	25.4	$	36.1
Weighted average common shares outstanding:
Basic		20,727			20,764			20,697		20,717
Effect of dilutive securities		218			195			238		226
Diluted		20,945			20,959			20,935		20,943
Earnings per common share – continuing operations:
Basic earnings per common share	$	0.70		$	1.00		$	1.23	$	1.74
Diluted earnings per common share		0.70			0.99			1.21		1.72
Other data:
Antidilutive securities excluded from computation of diluted earnings per common share		254			212			227		185