Note 14 - Selected Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Quarterly Financial Information [Table Text Block]

In millions, except per share amounts	March 31		June 30		September 30			December 31
2012
Operating revenues	$	1,404	$	686	$	614		$	1,218
Operating income		262		91		54			203
Net income attributable to AGL Resources Inc.		130		34		9			98
Basic earnings per common share attributable to AGL Resources Inc. common shareholders		1.12		0.28		0.08			0.84
Diluted earnings per common share attributable to AGL Resources Inc. common shareholders		1.11		0.28		0.08			0.84
2011
Operating revenues	$	878	$	375	$	295		$	790
Operating income		238		60		24			118
Net income (loss) attributable to AGL Resources Inc.		124		18		(3	)		33
Basic earnings (loss) per common share attributable to AGL Resources Inc. common shareholders		1.60		0.23		(0.04	)		0.37
Diluted earnings (loss) per common share attributable to AGL Resources Inc. common shareholders		1.59		0.23		(0.04	)		0.37
2010
Operating revenues	$	1,003	$	359	$	346		$	665
Operating income		253		48		62			137
Net income attributable to AGL Resources Inc.		134		14		22			64
Basic earnings per common share attributable to AGL Resources Inc. common shareholders		1.74		0.17		0.29			0.82
Diluted earnings per common share attributable to AGL Resources Inc. common shareholders		1.73		0.17		0.29			0.81