Note 8 - Debt and Credit Facilities (Tables)

12 Months Ended

Dec. 31, 2014

Debt Disclosure [Abstract]

Schedule of Debt [Table Text Block]

		December 31, 2014					December 31, 2013
Dollars in millions	Year(s) due	Weighted average interest rate (1)			Outstanding		Weighted average interest rate (1)			Outstanding
Short-term debt
Commercial paper - AGL Capital (2)	2015		0.3	%	$	590		0.4	%	$	857
Commercial paper - Nicor Gas (2)	2015		0.2			585		0.3			314
Total short-term debt			0.3	%	$	1,175		0.4	%	$	1,171
Current portion of long-term debt	2015		5.0	%	$	200		-	%	$	-
Long-term debt - excluding current portion
Senior notes	2016-2043		5.0	%	$	2,625		5.0	%	$	2,825
First mortgage bonds	2016-2038		5.6			500		5.6			500
Gas facility revenue bonds	2022-2033		0.9			200		1.0			200
Medium-term notes	2017-2027		7.8			181		7.8			181
Total principal long-term debt			4.9	%	$	3,506		4.9	%	$	3,706
Fair value adjustment of long-term debt (3)	2016-2038	n/a				80	n/a				91
Unamortized debt premium, net	n/a	n/a				16	n/a				16
Total non-principal long-term debt		n/a				96	n/a				107
Total long-term debt					$	3,602				$	3,813
Total debt					$	4,977				$	4,984

Schedule of Maturities of Long-term Debt [Table Text Block]

Year	Amount (in millions)
2015	$	200
2016		545
2017		22
2018		155
2019		350
Thereafter		2,434
Total	$	3,706

Schedule of Capitalization [Table Text Block]

	AGL Resources						Nicor Gas
	2014			2013			2014			2013
Debt-to-capitalization ratio		55	%		57	%		62	%		55	%