Note 8 - Debt and Credit Facilities (Tables)

12 Months Ended

Dec. 31, 2013

Debt Disclosure [Abstract]

Schedule of Debt [Table Text Block]

			December 31, 2013					December 31, 2012
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)		2014		0.4	%	$	857		0.5	%	$	1,063
Commercial paper- Nicor Gas (2)		2014		0.3			314		0.4			314
Total short-term debt				0.4	%	$	1,171		0.5	%	$	1,377
Current portion of long-term debt and capital leases
Current portion of long-term debt		n/a		-		$	-		4.6		$	225
Current portion of capital leases		n/a		-			-		4.9			1
Total current portion of long-term debt and capital leases				-		$	-		4.6	%	$	226
Long-term debt - excluding current portion
Senior notes		2015-2043		5.0	%	$	2,825		5.1	%	$	2,325
First mortgage bonds		2016-2038		5.6			500		5.6			500
Gas facility revenue bonds		2022-2033		1.0			200		1.2			200
Medium-term notes		2017-2027		7.8			181		7.8			181
Total principal long-term debt				4.9	%	$	3,706		5.0	%	$	3,206
Fair value adjustment of long-term debt (3)		2016-2038		n/a			91		n/a			103
Unamortized debt premium, net		n/a		n/a			16		n/a			18
Total non-principal long-term debt				n/a			107		n/a			121
Total long-term debt						$	3,813				$	3,327
Total debt						$	4,984				$	4,930

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

Year	Amount (in millions)
2014	$	-
2015		200
2016		545
2017		22
2018		155
Thereafter		2,784
Total	$	3,706

Schedule of Capitalization [Table Text Block]

	AGL Resources						Nicor Gas
	December 31,						December 31,
	2013			2012			2013			2012
Debt-to-capitalization ratio		57	%		58	%		55	%		55	%