Earnings Per Share (Notes)

12 Months Ended

Dec. 31, 2011

Earnings Per Share [Abstract]

Earnings Per Share

Earnings Per Share

The following sets forth basic and diluted earnings per common share available to IPG common stockholders.

	Years ended December 31,
	2011		2010			2009
Net income available to IPG common stockholders - basic	$	520.7	$	271.2		$	93.6
Adjustments: Effect of dilutive securities
Interest on 4.25% Notes	1.4		1.4			1.4
Interest on 4.75% Notes	4.1		4.0			0.0
Preferred stock dividends	11.6		0.0			0.0
Benefit from preferred stock repurchased 1	0.0		(21.7		)	0.0
Net income available to IPG common stockholders - diluted	$	537.8	$	254.9		$	95.0
Weighted-average number of common shares outstanding - basic	465.5		473.6			468.2
Add: Effect of dilutive securities
Restricted stock, stock options and other equity awards	9.1		11.3			7.7
4.25% Notes	33.0		32.2			32.2
4.75% Notes	16.5		16.1			0.0
Preferred stock outstanding	16.5		0.0			0.0
Preferred stock repurchased	0.0		8.9			0.0
Weighted-average number of common shares outstanding - diluted	540.6		542.1			508.1
Earnings per share available to IPG common stockholders - basic	$	1.12	$	0.57		$	0.20
Earnings per share available to IPG common stockholders - diluted	$	0.99	$	0.47		$	0.19

¹  For the year ended December 31, 2010, the benefit from the preferred stock repurchased is excluded from net income available to IPG common stockholders for purposes of calculating diluted earnings per share since the associated common shares, if converted, were dilutive. In addition, the benefit is also net of $4.0 of preferred dividends that were declared during the first quarter of 2010 and associated with the preferred stock repurchased.

For the year ended December 31,2009, we calculated basic EPS using the two-class method. The two-class method was required as our 4.50% Convertible Senior Notes due 2023 (the “4.50% Notes”) qualified as participating securities, having the right to receive dividends or dividend equivalents should dividends be declared on common stock. Under this method, earnings for the period (after deduction for contractual preferred stock dividends) was allocated on a pro-rata basis to the common stockholders and to the holders of participating securities based on their right to receive dividends. We retired the remaining outstanding aggregate principal amount of the 4.50% Notes in the fourth quarter of 2009.

The following table presents the potential shares excluded from the diluted earnings per share calculation because the effect of including these potential shares would be antidilutive.

	Years ended December 31,
	2011	2010	2009
4.75% Notes	0.0	0.0	16.1
4.50% Notes	0.0	0.0	0.6
Preferred stock outstanding	0.0	16.2	38.4
Total	0.0	16.2	55.1
Securities excluded from the diluted earnings per share calculation because the exercise price was greater than the average market price:
Stock options 1	8.9	15.6	21.2
Warrants 2	0.0	0.0	67.9

¹  These options are outstanding at the end of the respective periods. In any period in which the exercise price is less than the average market price, these options have the potential to be dilutive, and application of the treasury stock method would reduce this amount.

²  The potential dilutive impact of the warrants is based upon the difference between the market price of one share of our common stock and the stated exercise prices of the warrants, adjusted to reflect the period during which the warrants were outstanding. The warrants expired in June 2009.