Condensed Consolidated Statements of Income (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Operating revenues (includes revenue taxes of $50 in 2013 and $41 in 2012)	$ 1,709		$ 1,404
Operating expenses
Cost of goods sold	973		719
Operation and maintenance	259		245
Depreciation and amortization	107		104
Taxes other than income taxes	71		64
Nicor merger expenses			10	[1]
Total operating expenses	1,410		1,142
Operating income	299		262
Other income	5		4
Interest expense, net	(46)		(47)
Earnings before income taxes	258		219
Income tax expense	94		80
Net income	164		139
Less net income attributable to the noncontrolling interest	10		9
Net income attributable to AGL Resources Inc.	$ 154		$ 130
Per common share data
Basic earnings per common share attributable to AGL Resources Inc. common shareholders (in Dollars per share)	$ 1.31		$ 1.12
Diluted earnings per common share attributable to AGL Resources Inc. common shareholders (in Dollars per share)	$ 1.31		$ 1.11
Cash dividends declared per common share (in Dollars per share)	$ 0.47		$ 0.36
Weighted average number of common shares outstanding
Basic (in Shares)	117.4	[2]	116.7	[2]
Diluted (in Shares)	117.7		117.0

[1] Transaction expenses associated with the Nicor merger are shown separately to better compare year-over-year results.

[2] Daily weighted average shares outstanding.