Earnings Per Share

6 Months Ended

Jun. 30, 2012

Earnings Per Share [Abstract]

Earnings Per Share

Earnings Per Share

Computation of Earnings Per Share

	Second Quarter					Six Months
	2012		2011			2012			2011
	(in millions, except per share amounts)
Basic earnings per share (“EPS”):
Net income (loss) attributable to AGL	$	376.5	$	(43.1	)	$	(106.5	)	$	96.2
Less: Distributed and undistributed income (loss) available to nonvested shareholders	0.5		—			(0.2		)	0.1
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries	$	376.0	$	(43.1	)	$	(106.3	)	$	96.1
Basic shares	186.3		184.2			184.4			184.0
Basic EPS	$	2.02	$	(0.23	)	$	(0.58	)	$	0.52
Diluted EPS:
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries	$	376.0	$	(43.1	)	$	(106.3	)	$	96.1
Plus: Re-allocation of undistributed income (loss) available to nonvested shareholders of AGL and subsidiaries	—		—			—			—
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries	$	376.0	$	(43.1	)	$	(106.3	)	$	96.1
Basic shares	186.3		184.2			184.4			184.0
Effect of dilutive securities:
Options and restricted stock awards	0.7		—			—			0.9
Equity units	—		—			—			2.5
Diluted shares	187.0		184.2			184.4			187.4
Diluted EPS	$	2.01	$	(0.23	)	$	(0.58	)	$	0.51
Potentially dilutive securities excluded from computation of EPS because of antidilutive effect	13.0		19.5			15.9			2.9