CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current Assets
Cash and cash equivalents	$ 9,704	$ 9,541
Accounts receivable
Allowance for doubtful accounts	(6,549)	(12,946)
Accounts receivable, net of allowance for doubtful accounts of $12,946 at December 31, 2011, and $15,048 at December 31, 2010	277,900	231,925
Inventories
Storage gas inventory	32,205	44,047
Materials and supplies	28,291	26,420
Liquified natural gas in storage	3,498	3,545
Regulatory asset	45,515	57,143
Income tax receivable	6,664	7,343
Deferred income taxes	8,520	48,818
Prepayments and other	12,823	15,386
Total current assets	425,120	444,168
Property, Plant and Equipment
Oil and gas properties, successful efforts method	6,439,127	5,166,368
Less accumulated depreciation, depletion and amortization	1,765,241	1,382,526
Oil and gas properties, net	4,673,886	3,783,842
Utility plant	1,416,590	1,358,266
Less accumulated depreciation	573,947	544,838
Utility plant, net	842,643	813,428
Other property, net	25,107	23,506
Total property, plant and equipment, net	5,541,636	4,620,776
Other Assets
Regulatory asset	110,566	95,633
Pension and other postretirement assets	1,404	0
Long-term derivative instruments	40,577	31,056
Deferred charges and other	56,587	45,783
Total other assets	209,134	172,472
TOTAL ASSETS	6,175,890	5,237,416
Current Liabilities
Long-term debt due within one year	50,000	1,000
Notes payable to banks	643,000	15,000
Accounts payable	257,579	302,048
Accrued taxes	30,076	32,359
Customers' deposits	24,705	23,950
Amounts due customers	19,718	21,065
Accrued wages and benefits	24,984	35,258
Regulatory liability	45,116	58,279
Royalty payable	34,426	22,592
Deferred income taxes	24,667	1,469
Other	30,178	32,328
Total current liabilities	1,159,782	543,879
Long-term debt	1,103,528	1,153,700
Deferred Credits and Other Liabilities
Asset retirement obligation	118,023	107,340
Pension and other postretirement liabilities	110,282	62,532
Regulatory liability	80,404	87,234
Deferred income taxes	905,601	806,127
Long-term derivative instruments	11,305	34,663
Other	10,275	9,778
Total deferred credits and other liabilities	1,235,890	1,107,674
Commitments and Contingencies
Shareholders' Equity
Preferred stock, cumulative $0.01 par value	0	0
Common shareholders' equity
Common stock, $0.01 par value	751	750
Premium on capital stock	492,108	482,918
Capital surplus	2,802	2,802
Retained earnings	2,314,055	2,100,885
Accumulated other comprehensive income (loss), net of tax
Unrealized gain (loss) on hedges, net	46,352	9,273
Pension and postretirement plans	(52,507)	(38,584)
Interest rate swap	(2,156)	(941)
Deferred compensation plan	2,774	3,511
Treasury stock, at cost; 3,036,549 shares and 3,024,847 shares at December 31, 2011 and 2010, respectively	(127,489)	(128,451)
Total shareholders' equity	2,676,690	2,432,163
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	6,175,890	5,237,416
Alabama Gas Corporation
Current Assets
Cash and cash equivalents	5,559	7,817
Accounts receivable
Gas	94,011	96,812
Other	5,117	6,858
Affiliated companies	5,742	2,841
Allowance for doubtful accounts	(5,700)	(12,100)
Inventories
Storage gas inventory	32,205	44,047
Materials and supplies	5,528	4,183
Liquified natural gas in storage	3,498	3,545
Regulatory asset	45,515	57,143
Income tax receivable	2,762	9,762
Deferred income taxes	18,799	21,986
Prepayments and other	4,451	4,422
Total current assets	217,487	247,316
Property, Plant and Equipment
Utility plant	1,416,590	1,358,266
Less accumulated depreciation	573,947	544,838
Utility plant, net	842,643	813,428
Other property, net	42	43
Other Assets
Regulatory asset	110,566	95,633
Pension and other postretirement assets	848	0
Deferred charges and other	11,290	10,380
Total other assets	122,704	106,013
TOTAL ASSETS	1,182,876	1,166,800
Current Liabilities
Long-term debt due within one year	0	0
Notes payable to banks	77,000	15,000
Accounts payable	51,741	110,552
Accrued taxes	24,186	26,861
Customers' deposits	24,705	23,950
Amounts due customers	19,718	21,065
Accrued wages and benefits	6,703	12,971
Regulatory liability	45,116	58,279
Deferred income taxes	1,401	1,348
Other	9,018	9,250
Total current liabilities	258,187	277,928
Long-term debt	250,028	250,246
Deferred Credits and Other Liabilities
Pension and other postretirement liabilities	43,611	21,383
Regulatory liability	80,404	87,234
Deferred income taxes	189,381	181,492
Long-term derivative instruments	0	3,070
Other	762	709
Total deferred credits and other liabilities	314,158	293,888
Commitments and Contingencies
Shareholders' Equity
Preferred stock, cumulative $0.01 par value	0	0
Common shareholders' equity
Common stock, $0.01 par value	20	20
Premium on capital stock	31,682	31,682
Capital surplus	2,802	2,802
Retained earnings	325,999	310,234
Accumulated other comprehensive income (loss), net of tax
Total shareholders' equity	360,503	344,738
Total capitalization	610,531	594,984
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 1,182,876	$ 1,166,800