Derivative Instruments and Hedging Activities (Tables)

12 Months Ended

Dec. 31, 2023

Derivative [Line Items]

Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block]

The following tables provide information on gains or losses recognized in AOCI / (AOCL) for the cash flow hedges for the periods indicated:

	Interest Rate Hedges for the Years Ended December 31,
$ in thousands (net of tax)	2023		2022		2021
Beginning accumulated derivative gain / (loss) in AOCI / (AOCL)	$	22,269	$	(29,407)	$	(43,420)
Net gains associated with current period hedging transactions	1,594		46,245		10,393
Net losses reclassified to interest expense	5,431		5,431		3,620
Ending accumulated derivative gain / (loss) in AOCI / (AOCL)	$	29,294	$	22,269	$	(29,407)
Loss expected to be reclassified to earnings in the next twelve months	$	(5,375)
Maximum length of time that we are hedging our exposure to variability in future cash flows related to forecasted transactions (in months)	9

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]

			December 31,
Commodity	Hedging Designation	Balance sheet classification	2023		2022
FTRs	Not a Cash Flow Hedge	Derivative assets, current	$	1,388	$	7,545
Interest rate hedges	Cash Flow Hedge	Derivative assets, current	$	14,294	$	—
Interest rate hedges	Cash Flow Hedge	Derivative assets, non-current	$	—	$	12,172

Schedule of Derivative Instruments [Table Text Block]

At December 31, 2023, AES Indiana's outstanding derivative instruments were as follows:

Commodity	Accounting Treatment (a)	Unit	Notional (in thousands)		Sales (in thousands)		Net Notional (in thousands)
Interest rate hedges	Designated	USD	$	400,000	$	—	$	400,000
FTRs	Not Designated	MWh	3,919		—		3,919

(a)    Refers to whether the derivative instruments have been designated as a cash flow hedge.

Subsidiaries [Member]

Derivative [Line Items]

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]

			December 31,
Commodity	Hedging Designation	Balance sheet classification	2023		2022
FTRs	Not a Cash Flow Hedge	Prepayments and other current assets	$	1,388	$	7,545

Schedule of Derivative Instruments [Table Text Block]

At December 31, 2023, AES Indiana's outstanding derivative instruments were as follows:

Commodity	Accounting Treatment (a)	Unit	Notional (in thousands)	Sales (in thousands)	Net Notional (in thousands)
FTRs	Not Designated	MWh	3,919	—	3,919

(a)    Refers to whether the derivative instruments have been designated as a cash flow hedge.