Shareholders' Equity (Details) - USD ($) $ in Millions		9 Months Ended
	Apr. 01, 2015	Sep. 30, 2015
Common Stock [Member]
Class of Stock [Line Items]
Number of shares issued and sold (shares)	11,818,828
Value of shares issued and sold	$ 214.4
CDPQ [Member]
Class of Stock [Line Items]
Percentage of direct ownership share of IPALCO		11.60%
Percentage of direct and indirect ownership share of IPALCO	24.90%