Earnings Per Share

6 Months Ended

Jun. 30, 2013

Earnings Per Share [Abstract]

Earnings Per Share

Earnings Per Share

Computation of Earnings Per Share

	Second Quarter				Six Months
	2013		2012		2013		2012
	(in millions, except per share amounts)
Basic earnings per share ("EPS"):
Net income (loss) attributable to AGL	$	219	$	377	$	75	$	(106	)
Less: Distributed and undistributed income (loss) available to nonvested shareholders	0		1		0		0
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	219	$	376	$	75	$	(106	)
Basic shares	187.8		186.3		190.8		184.4
Basic EPS	$	1.17	$	2.02	$	0.39	$	(0.58	)
Diluted EPS:
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	219	$	376	$	75	$	(106	)
Plus: Re-allocation of undistributed income (loss) available to nonvested shareholders of AGL and subsidiaries	0		—		0		—
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, diluted	$	219	$	376	$	75	$	(106	)
Basic shares	187.8		186.3		190.8		184.4
Effect of dilutive securities:
Options and restricted stock awards	1.0		0.7		0.9		—
Equity units	—		—		—		—
Diluted shares	188.8		187.0		191.7		184.4
Diluted EPS	$	1.16	$	2.01	$	0.39	$	(0.58	)
Potentially dilutive securities excluded from computation of EPS because of antidilutive effect	2.0		13.0		3.6		15.9