Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net income	$ 44	$ 60	$ 249	$ 356
Retirement benefit plans
Reclassification of actuarial losses to net benefit cost (net of income tax of $2 and $4 for the three and six months ended June 30, 2015, and $2 and $3 for the three and six months ended June 30, 2014)	4	4	7	5
Reclassification of prior service credits to net benefit cost		(1)		(1)
Retirement benefit plans, net	4	3	7	4
Cash flow hedges, net of tax
Net derivative instruments gain arising during the period (net of income tax of $16 and $17 for the three and six months ended June 30, 2015)	25		27	4
Reclassification of realized derivative instruments (gain) loss to net income (net of income tax of $(1) for the three and six months ended June 30, 2014)	4	(1)	4	(5)
Cash flow hedges, net	29	(1)	31	(1)
Other comprehensive income, net of tax	33	2	38	3
Comprehensive income	77	62	287	359
Less comprehensive income attributable to noncontrolling interest	3	2	15	14
Comprehensive income attributable to AGL Resources Inc.	$ 74	$ 60	$ 272	$ 345