Regulatory Assets and Liabilities (Tables) (Alabama Gas Corporation [Member])

6 Months Ended

Jun. 30, 2011

Alabama Gas Corporation [Member]

Regulatory Assets and Liabilities [Line Items]

Schedule of Regulatory Assets and Liabilities [Table Text Block]

The following table details regulatory assets and liabilities on the balance sheets:

(in thousands)	June 30, 2011				December 31, 2010
	Current		Noncurrent		Current		Noncurrent
Regulatory assets:
Pension and postretirement assets	$	170	$	58,469	$	132	$	60,284
Accretion and depreciation for asset retirement obligation	—		8,898		—		8,681
Risk management activities	32,159		17,657		27,906		32,461
RSE adjustment	25		—		25		—
Enhanced stability reserve	—		4,395		—		3,794
Other	209		46		223		145
Total regulatory assets	$	32,563	$	89,465	$	28,286	$	105,365
Regulatory liabilities:
RSE adjustment	$	7,696	$	—	$	4,147	$	—
Unbilled service margin	6,957		—		34,197		—
Postretirement liabilities	—		959		—		754
Gas supply adjustment	29,695		—		14,990		—
Asset removal costs, net	—		7,665		—		6,913
Refundable negative salvage	20,643		71,896		22,336		90,504
Asset retirement obligation	—		11,611		—		11,439
Other	33		820		33		837
Total regulatory liabilities	$	65,024	$	92,951	$	75,703	$	110,447