Consolidated Condensed Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current Assets
Cash and cash equivalents	$ 20,303	$ 9,704
Accounts receivable
Allowance for doubtful accounts	(5,446)	(6,549)
Accounts receivable, net of allowance for doubtful accounts of $5,446 at March 31, 2013, and $6,549 at December 31, 2012	241,507	277,900
Inventories
Storage gas inventory	9,264	32,205
Materials and supplies	25,283	28,291
Liquified natural gas in storage	3,109	3,498
Regulatory asset	24,135	45,515
Income tax receivable	1,883	6,664
Deferred income taxes	27,278	8,520
Prepayments and other	12,084	12,823
Total current assets	364,846	425,120
Property, Plant and Equipment
Oil and gas properties, successful efforts method	6,712,635	6,439,127
Less accumulated depreciation, depletion and amortization	1,858,960	1,765,241
Oil and gas properties, net	4,853,675	4,673,886
Utility plant	1,435,924	1,416,590
Less accumulated depreciation	583,625	573,947
Utility plant, net	852,299	842,643
Other property, net	25,218	25,107
Total property, plant and equipment, net	5,731,192	5,541,636
Other Assets
Regulatory asset	109,002	110,566
Pension and other postretirement assets	1,732	1,404
Long-term derivative instruments	26,199	40,577
Deferred charges and other	60,207	56,587
Total other assets	197,140	209,134
TOTAL ASSETS	6,293,178	6,175,890
Current Liabilities
Long-term debt due within one year	75,000	50,000
Notes payable to banks	712,000	643,000
Accounts payable	285,920	257,579
Accrued taxes	38,666	30,076
Customers' deposits	25,231	24,705
Amounts due customers	10,580	19,718
Accrued wages and benefits	17,587	24,984
Regulatory liability	41,886	45,116
Royalty payable	38,771	34,426
Other	27,344	30,178
Total current liabilities	1,272,985	1,159,782
Long-term debt	1,078,529	1,103,528
Deferred Credits and Other Liabilities
Asset retirement obligation	120,599	118,023
Pension and other postretirement liabilities	106,515	110,282
Regulatory liability	68,812	80,404
Long-term derivative instruments	9,705	11,305
Deferred income taxes	931,628	905,601
Other	12,981	10,275
Total deferred credits and other liabilities	1,250,240	1,235,890
Commitments and Contingencies
Shareholders’ Equity
Preferred stock, cumulative $0.01 par value	0	0
Common shareholders’ equity
Common stock, $0.01 par value	751	751
Premium on capital stock	493,928	492,108
Capital surplus	2,802	2,802
Retained earnings	2,360,274	2,314,055
Accumulated other comprehensive income (loss), net of tax
Unrealized gain on hedges, net	8,834	46,352
Pension and postretirement plans	(50,699)	(52,507)
Interest rate swap	(1,910)	(2,156)
Deferred compensation plan	3,416	2,774
Treasury stock, at cost: 2,969,784 shares at March 31, 2013, and 2,998,620 shares at December 31, 2012	(125,972)	(127,489)
Total shareholders' equity	2,691,424	2,676,690
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	6,293,178	6,175,890
Alabama Gas Corporation
Current Assets
Cash and cash equivalents	17,260	5,559
Accounts receivable
Gas	99,657	94,011
Other	5,698	5,117
Affiliated companies	4,620	5,742
Allowance for doubtful accounts	(4,600)	(5,700)
Inventories
Storage gas inventory	9,264	32,205
Materials and supplies	5,541	5,528
Liquified natural gas in storage	3,109	3,498
Regulatory asset	24,135	45,515
Income tax receivable	0	2,762
Deferred income taxes	18,669	18,799
Prepayments and other	3,674	4,451
Total current assets	187,027	217,487
Property, Plant and Equipment
Utility plant	1,435,924	1,416,590
Less accumulated depreciation	583,625	573,947
Utility plant, net	852,299	842,643
Other property, net	41	42
Other Assets
Regulatory asset	109,002	110,566
Pension and other postretirement assets	1,103	848
Deferred charges and other	11,098	11,290
Total other assets	121,203	122,704
TOTAL ASSETS	1,160,570	1,182,876
Current Liabilities
Notes payable to banks	30,000	77,000
Accounts payable	38,264	51,741
Accrued taxes	47,068	24,186
Customers' deposits	25,231	24,705
Amounts due customers	10,580	19,718
Accrued wages and benefits	6,184	6,703
Regulatory liability	41,886	45,116
Other	9,535	9,018
Total current liabilities	208,748	258,187
Long-term debt	250,018	250,028
Deferred Credits and Other Liabilities
Pension and other postretirement liabilities	39,914	43,611
Regulatory liability	68,812	80,404
Deferred income taxes	192,271	189,381
Other	1,520	762
Total deferred credits and other liabilities	302,517	314,158
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	364,783	325,999
Accumulated other comprehensive income (loss), net of tax
Total shareholders' equity	399,287	360,503
Total capitalization	649,305	610,531
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 1,160,570	$ 1,182,876