Note 7 - Debt and Credit Facilities (Tables)

6 Months Ended

Jun. 30, 2015

Debt Disclosure [Abstract]

Schedule of Debt [Table Text Block]

			June 30, 2015									June 30, 2014
Dollars in millions	Year(s) due		Weighted average interest rate (1)			Outstanding			December 31, 2014			Weighted average interest rate (1)			Outstanding
Short-term debt
Commercial paper - AGL Capital (2)		2015		0.5	%	$	269		$	590			0.3	%	$	236
Commercial paper - Nicor Gas (2)		2015		0.4			190			585			0.2			212
Total short-term debt				0.4	%	$	459		$	1,175			0.3	%	$	448
Current portion of long-term debt		2016		4.6	%	$	125		$	200			5.0	%	$	200
Long-term debt - excluding current portion
Senior notes		2016-2043		5.0	%	$	2,625		$	2,625			5.0	%	$	2,625
First mortgage bonds		2019-2038		5.9			375			500			5.6			500
Gas facility revenue bonds		2022-2033		0.9			200			200			0.9			200
Medium-term notes		2017-2027		7.8			181			181			7.8			181
Total principal long-term debt				4.9			3,381			3,506			4.9			3,506
Fair value adjustment of long-term debt (3)		n/a		n/a			74			80			n/a			85
Unamortized debt premium and issuance costs, net		n/a		n/a			(3	)		(5	)		n/a			(6	)
Total non-principal long-term debt				n/a			71			75			n/a			79
Total long-term debt – excluding current portion						$	3,452		$	3,581					$	3,585
Total debt						$	4,036		$	4,956					$	4,233

Schedule of Capitalization [Table Text Block]

	AGL Resources						Nicor Gas
	June 30,		Dec. 31,		June 30,		June 30,		Dec. 31,		June 30,
	2015		2014		2014		2015		2014		2014
Debt covenants (1)		49%		55%		51%		49%		62%		52%