CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Revenues
Oil and gas operations	$ 1,165,580	$ 948,526	$ 958,762
Natural gas distribution	451,589	534,953	619,772
Total operating revenues	1,617,169	1,483,479	1,578,534
Operating Expenses
Cost of gas	142,228	233,523	316,988
Operations and maintenance	477,883	419,119	429,165
Depreciation, depletion and amortization	419,598	283,997	247,865
Asset impairment	21,545	0	0
Income taxes
Current	19,420	16,660	33,150
Deferred	124,399	129,041	133,840
Taxes, other than income taxes	88,989	91,734	84,961
Accretion expense	7,534	6,837	6,178
Total operating expenses	1,157,777	1,035,210	1,085,157
Operating Income (Expense)	459,392	448,269	493,377
Other Income (Expense)
Interest expense	65,556	44,822	39,222
Other income	4,448	2,334	4,285
Other expense	(903)	(456)	(643)
Total other income (expense)	(62,011)	(42,944)	(35,580)
Interest Charges
Income Before Income Taxes	397,381	405,325	457,797
Income tax expense	143,819	145,701	166,990
Net income	253,562	259,624	290,807
Diluted earnings per average common share	$ 3.51	$ 3.59	$ 4.04
Basic earnings per average common share	$ 3.52	$ 3.60	$ 4.05
Dividends Per Common Share (dollars per share)	$ 0.56	$ 0.54	$ 0.52
Diluted Average Common Shares Outstanding	72,316,214	72,332,369	72,050,997
Basic Average Common Shares Outstanding	72,119,021	72,055,661	71,845,463
Alabama Gas Corporation
Operating Revenues
Natural gas distribution	451,589	534,953	619,772
Operating Expenses
Cost of gas	142,228	233,523	316,988
Operations and maintenance	141,334	139,030	128,830
Depreciation, depletion and amortization	42,270	39,916	44,042
Income taxes
Current	18,966	(1,388)	1,014
Deferred	11,278	28,058	28,861
Taxes, other than income taxes	32,541	36,268	41,529
Total operating expenses	388,617	475,407	561,264
Operating Income (Expense)	62,972	59,546	58,508
Other Income (Expense)
Interest expense	16,284	14,740	13,894
Allowance for funds used during construction	623	807	808
Other income	2,382	1,309	1,923
Other expense	(291)	(320)	(462)
Total other income (expense)	2,714	1,796	2,269
Interest Charges
Interest on long-term debt	13,744	12,100	11,907
Other interest charges	2,540	2,640	1,987
Income tax expense	30,244	26,670	29,875
Net income	$ 49,402	$ 46,602	$ 46,883