UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Comprehensive income attributable to AGL Resources Inc. (net of tax)
Net (loss) income attributable to AGL Resources Inc	$ (3)	$ 22	$ 139	$ 170
Derivative financial instruments unrealized losses arising during the period	(1)	(6)	(2)	(23)
Reclassification of derivative financial instruments realized losses included in net income	1	1	1	7
Other comprehensive loss	0	(5)	(1)	(16)
Comprehensive (loss) income	(3)	17	138	154
Comprehensive income attributable to noncontrolling interest (net of tax)
Less net (loss) income attributable to the noncontrolling interest (Note 8)	(1)	(1)	10	10
Derivative financial instruments unrealized losses arising during the period	0	0	0	(1)
Reclassification of derivative financial instruments realized losses included in net income	0	0	0	1
Other comprehensive income	0	0	0	0
Comprehensive (loss) income	(1)	(1)	10	10
Total comprehensive income (net of tax) including portion attributable to noncontrolling interest (net of tax)
Net (loss) income	(4)	21	149	180
Derivative financial instruments unrealized losses arising during the period	(1)	(6)	(2)	(24)
Reclassification of derivative financial instruments realized losses included in net income	1	1	1	8
Other comprehensive loss	0	(5)	(1)	(16)
Comprehensive (loss) income	$ (4)	$ 16	$ 148	$ 164