Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2017

Earnings Per Share [Abstract]

Schedule of computation of basic and diluted earnings per share

Computation of EPS

	Third Quarter				Nine Months
	2017		2016		2017		2016
	(in millions)
Basic EPS:
Net income (loss) attributable to AGL	$	208	$	479	$	678	$	684
Less: Distributed and undistributed income (loss) available to nonvested shareholders	0		1		1		1
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	208	$	478	$	677	$	683
Basic shares	118.7		131.9		121.8		134.0
Basic EPS	$	1.75	$	3.63	$	5.56	$	5.10
Diluted EPS:
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	208	$	478	$	677	$	683
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	$	208	$	478	$	677	$	683
Basic shares	118.7		131.9		121.8		134.0
Dilutive securities:
Options and restricted stock awards	2.0		0.9		1.7		0.9
Diluted shares	120.7		132.8		123.5		134.9
Diluted EPS	$	1.72	$	3.60	$	5.48	$	5.06
Potentially dilutive securities excluded from computation of EPS because of antidilutive effect	—		0.0		0.1		0.5

Schedule of antidilutive securities excluded from computation of earnings per share

Computation of EPS

	Third Quarter				Nine Months
	2017		2016		2017		2016
	(in millions)
Basic EPS:
Net income (loss) attributable to AGL	$	208	$	479	$	678	$	684
Less: Distributed and undistributed income (loss) available to nonvested shareholders	0		1		1		1
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	208	$	478	$	677	$	683
Basic shares	118.7		131.9		121.8		134.0
Basic EPS	$	1.75	$	3.63	$	5.56	$	5.10
Diluted EPS:
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	208	$	478	$	677	$	683
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	$	208	$	478	$	677	$	683
Basic shares	118.7		131.9		121.8		134.0
Dilutive securities:
Options and restricted stock awards	2.0		0.9		1.7		0.9
Diluted shares	120.7		132.8		123.5		134.9
Diluted EPS	$	1.72	$	3.60	$	5.48	$	5.06
Potentially dilutive securities excluded from computation of EPS because of antidilutive effect	—		0.0		0.1		0.5