Indebtedness (Schedule Long-Term Indebtedness) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Jul. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Unamortized discount - net	$ (4,600)		$ (4,300)
Long-term debt	2,215,665		1,951,013
Less: Current Portion of Long-term Debt	131,850		0
Net Consolidated IPALCO Long-term Debt	2,083,815		1,951,013
Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
First mortgage bonds	1,411,060		1,152,360
Unamortized discount - net	(4,240)		(2,940)
Long-term debt	1,411,060		1,152,360
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.90% Due January 2016 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 30,000		30,000
Debt, stated interest rate	4.90%
Debt due date	Jan. 01, 2016
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.90% Due January 2016 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 41,850		41,850
Debt, stated interest rate	4.90%
Debt due date	Jan. 01, 2016
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.90% Due January 2016 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 60,000		60,000
Debt, stated interest rate	4.90%
Debt due date	Jan. 01, 2016
Indianapolis Power And Light Company [Member] | First Mortgage Bond 5.40% Due August 2017 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 24,650		24,650
Debt, stated interest rate	5.40%
Debt due date	Aug. 01, 2017
Indianapolis Power And Light Company [Member] | First Mortgage Bond 3.875% Due August 2021 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 55,000		55,000
Debt, stated interest rate	3.875%
Debt due date	Aug. 01, 2021
Indianapolis Power And Light Company [Member] | First Mortgage Bond 3.875% Due August 2021 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 40,000		40,000
Debt, stated interest rate	3.875%
Debt due date	Aug. 01, 2021
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.55% Due December 2024 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 40,000		40,000
Debt, stated interest rate	4.55%
Debt due date	Dec. 01, 2024
Indianapolis Power And Light Company [Member] | First Mortgage Bond 6.60% Due January 2034 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 100,000		100,000
Debt, stated interest rate	6.60%
Debt due date	Jan. 01, 2034
Indianapolis Power And Light Company [Member] | First Mortgage Bond 6.05% Due October 2036 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 158,800		158,800
Debt, stated interest rate	6.05%
Debt due date	Oct. 01, 2036
Indianapolis Power And Light Company [Member] | First Mortgage Bond 6.60% Due June 2037 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 165,000		165,000
Debt, stated interest rate	6.60%
Debt due date	Jun. 01, 2037
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.875% Due November 2041 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 140,000		140,000
Debt, stated interest rate	4.875%
Debt due date	Nov. 01, 2041
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.65% Due June 2043 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 170,000		170,000
Debt, stated interest rate	4.65%
Debt due date	Jun. 01, 2043
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.50% Due June 2044[Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 130,000		130,000
Debt, stated interest rate	4.50%
Debt due date	Jun. 01, 2044
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.70%, Due September 2045 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 260,000		0
Debt, stated interest rate	4.70%
Debt due date	Sep. 01, 2045
Ipalco Enterprises, Inc. [Member]
Debt Instrument [Line Items]
Unamortized discount - net	$ (395)		(1,347)
Net Consolidated IPALCO Long-term Debt	804,605		798,653
Ipalco Enterprises, Inc. [Member] | 7.25% Senior Secured Notes [Member]
Debt Instrument [Line Items]
Long-term debt	$ 0		400,000
Less: Current Portion of Long-term Debt		$ 33,500
Debt, stated interest rate	7.25%
Debt due date	Apr. 01, 2016
Ipalco Enterprises, Inc. [Member] | 5.00% Senior Secured Notes [Member]
Debt Instrument [Line Items]
Long-term debt	$ 400,000		400,000
Debt, stated interest rate	5.00%
Debt due date	May 01, 2018
Ipalco Enterprises, Inc. [Member] | 3.45% Senior Secured Notes [Member]
Debt Instrument [Line Items]
Long-term debt	$ 405,000		$ 0
Debt, stated interest rate	3.45%
Debt due date	Jul. 01, 2020