Condensed Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
UTILITY OPERATING REVENUES	$ 1,229,777	$ 1,171,924	$ 1,144,903
UTILITY OPERATING EXPENSES:
Fuel	340,647	334,385	322,541
Other operating expenses	217,124	203,286	196,166
Power purchased	121,238	90,159	55,456
Maintenance	99,568	119,152	118,883
Depreciation and amortization	176,843	167,245	164,102
Taxes other than income taxes	44,295	42,435	39,378
Income taxes - net	67,162	62,609	75,939
Total utility operating expenses	1,066,877	1,019,271	972,465
UTILITY OPERATING INCOME	162,900	152,653	172,438
OTHER INCOME AND (DEDUCTIONS):
Allowance for equity funds used during construction	1,087	3,950	3,990
Loss on early extinguishment of debt		(15,422)
Miscellaneous income and (deductions) - net	(2,290)	6,963	(3,311)
Income tax benefit applicable to nonoperating income	19,463	25,476	25,410
Total other income and (deductions) - net	18,260	20,967	26,089
INTEREST AND OTHER CHARGES:
Interest on long-term debt	103,435	109,233	114,707
Other interest	1,913	1,786	2,136
Allowance for borrowed funds used during construction	(1,059)	(2,674)	(2,437)
Amortization of redemption premiums and expense on debt	4,875	4,700	4,174
Total interest and other charges - net	109,164	113,045	118,580
NET INCOME	71,996	60,575	79,947
LESS: PREFERRED DIVIDENDS OF SUBSIDIARY	3,213	3,213	3,213
NET INCOME APPLICABLE TO COMMON STOCK	68,783	57,362	76,734
ADD OTHER COMPREHENSIVE INCOME:
Unrealized loss on available for sale investment			(197)
Gain on sale of available for sale investment		197
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON STOCK	68,783	57,559	76,537
Indianapolis Power And Light Company [Member]
UTILITY OPERATING REVENUES	1,229,777	1,171,924	1,144,903
UTILITY OPERATING EXPENSES:
Fuel	340,647	334,385	322,541
Other operating expenses	217,124	203,286	196,166
Power purchased	121,238	90,159	55,456
Maintenance	99,568	119,152	118,883
Depreciation and amortization	176,843	167,245	164,102
Taxes other than income taxes	44,295	42,435	39,378
Income taxes - net	67,162	62,609	75,939
Total utility operating expenses	1,066,877	1,019,271	972,465
UTILITY OPERATING INCOME	162,900	152,653	172,438
OTHER INCOME AND (DEDUCTIONS):
Allowance for equity funds used during construction	1,087	3,950	3,990
Miscellaneous income and (deductions) - net	(1,457)	9,431	(1,693)
Income tax benefit applicable to nonoperating income	(654)	(3,799)	252
Total other income and (deductions) - net	(1,024)	9,582	2,549
INTEREST AND OTHER CHARGES:
Interest on long-term debt	54,435	55,231	53,363
Other interest	1,913	1,786	2,136
Allowance for borrowed funds used during construction	(1,059)	(2,674)	(2,437)
Amortization of redemption premiums and expense on debt	2,458	2,494	2,137
Total interest and other charges - net	57,747	56,837	55,199
NET INCOME	104,129	105,398	119,788
LESS: PREFERRED DIVIDENDS OF SUBSIDIARY	3,213	3,213	3,213
NET INCOME APPLICABLE TO COMMON STOCK	100,916	102,185	116,575
ADD OTHER COMPREHENSIVE INCOME:
Unrealized loss on available for sale investment			(197)
Gain on sale of available for sale investment		197
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON STOCK	$ 100,916	$ 102,382	$ 116,378