CONSOLIDATED STATEMENTS OF EQUITY (USD $) In Millions	Common Stock [Member]	Accumulated Other Comprehensive Loss [Member]	Premium on Common Stock [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]	Total
AGL Resources Inc. Common Shareholders Equity, Beginning Balance at Dec. 31, 2008	$ 390	$ (134)	$ 676	$ 763	$ (43)	$ 32	$ 1,684
Common stock shares, Beginning Balance (in shares) at Dec. 31, 2008	76.9
Profit Loss				222		27	249
Other comprehensive loss		18					18
Dividends paid on common shares				(132)	5		(127)
Distributions to noncontrolling interest (Note 8)						(20)	(20)
Issuance of treasury shares, amount			(4)	(5)	17		8
Issuance of treasury shares, shares(in shares)	0.6
Stock-based compensation expense (net of tax)			7				7
AGL Resources Inc. Common Shareholders Equity, Ending Balance at Dec. 31, 2009	390	(116)	679	848	(21)	39	1,819
Common stock shares, Ending Balance (in shares) at Dec. 31, 2009	77.5
Profit Loss				234		16	250
Other comprehensive loss		(33)				1	(32)
Dividends paid on common shares				(136)	3		(133)
Purchase of additional 15% ownership interest in SouthStar		(1)	(51)			(6)	(58)
Distributions to noncontrolling interest (Note 8)						(27)	(27)
Purchase of treasury shares, amount					(7)		(7)
Purchase of treasury shares, shares (in shares)	(0.2)						0.2
Issuance of treasury shares, amount	1		(5)	(3)	22		15
Issuance of treasury shares, shares(in shares)	0.7
Stock-based compensation expense (net of tax)			8		1		9
AGL Resources Inc. Common Shareholders Equity, Ending Balance at Dec. 31, 2010	391	(150)	631	943	(2)	23	1,836
Common stock shares, Ending Balance (in shares) at Dec. 31, 2010	78.0
Profit Loss				172		14	186
Other comprehensive loss		(67)					(67)
Dividends paid on common shares			0	(148)			(148)
Benefit Dividend Reinvestment And Stock Purchase Plans, Shares (in shares)	0.8
Distributions to noncontrolling interest (Note 8)						(16)	(16)
Benefit Dividend Reinvestment And Stock Purchase Plans, Value	4		18		(3)		19
Purchase of treasury shares, amount					(2)		(2)
Purchase of treasury shares, shares (in shares)	0						0.1
Stock-based compensation expense (net of tax)			8				8
Stock Issued During Period Shares Acquisitions	38.2
Stock Issued During Period Value Acquisitions	191		1,332				1,523
AGL Resources Inc. Common Shareholders Equity, Ending Balance at Dec. 31, 2011	$ 586	$ (217)	$ 1,989	$ 967	$ (7)	$ 21	$ 3,339
Common stock shares, Ending Balance (in shares) at Dec. 31, 2011	117.0