Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2015

Earnings Per Share [Abstract]

Schedule of computation of basic and diluted earnings per share

Computation of Earnings Per Share

	Third Quarter				Nine Months
	2015		2014		2015		2014
	(in millions)
Basic earnings per share ("EPS"):
Net income (loss) attributable to AGL	$	129	$	355	$	627	$	556
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	$	129	$	354	$	627	$	556
Basic shares	145.8		168.8		150.7		176.4
Basic EPS	$	0.88	$	2.10	$	4.16	$	3.15
Diluted EPS:
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	129	$	354	$	627	$	556
Plus: Re-allocation of undistributed income (loss) available to nonvested shareholders of AGL and subsidiaries	0		0		0		0
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, diluted	$	129	$	354	$	627	$	556
Basic shares	145.8		168.8		150.7		176.4
Effect of dilutive securities:
Options and restricted stock awards	0.7		0.9		0.9		1.0
Diluted shares	146.5		169.7		151.6		177.4
Diluted EPS	$	0.88	$	2.09	$	4.13	$	3.13
Potentially dilutive securities excluded from computation of EPS because of antidilutive effect	1.3		1.9		0.7		1.6

Schedule of antidilutive securities excluded from computation of earnings per share

Computation of Earnings Per Share

	Third Quarter				Nine Months
	2015		2014		2015		2014
	(in millions)
Basic earnings per share ("EPS"):
Net income (loss) attributable to AGL	$	129	$	355	$	627	$	556
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	$	129	$	354	$	627	$	556
Basic shares	145.8		168.8		150.7		176.4
Basic EPS	$	0.88	$	2.10	$	4.16	$	3.15
Diluted EPS:
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	129	$	354	$	627	$	556
Plus: Re-allocation of undistributed income (loss) available to nonvested shareholders of AGL and subsidiaries	0		0		0		0
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, diluted	$	129	$	354	$	627	$	556
Basic shares	145.8		168.8		150.7		176.4
Effect of dilutive securities:
Options and restricted stock awards	0.7		0.9		0.9		1.0
Diluted shares	146.5		169.7		151.6		177.4
Diluted EPS	$	0.88	$	2.09	$	4.13	$	3.13
Potentially dilutive securities excluded from computation of EPS because of antidilutive effect	1.3		1.9		0.7		1.6