Redeemable Stock of Subsidiaries (Narrative) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) quarter series $ / shares	Dec. 31, 2014 USD ($) quarter $ / shares
Temporary Equity [Line Items]
Sale of Stock, Consideration Received Per Transaction	$ 460	$ 0
Redeemable stock of subsidiaries	538	78
Temporary equity carrying amount	78	78
IPL Subsidiary
Temporary Equity [Line Items]
Temporary equity carrying amount	$ 60	60
Number of preferred stock series | series	5
Temporary equity annual dividend requirement	$ 3	$ 3
Number of consecutive quarters without paid dividends to invoke board of directors election rule | quarter	4	4,000,000
IPL Subsidiary | Minimum
Temporary Equity [Line Items]
Temporary equity, redemption price per share | $ / shares	$ 100	$ 100,000,000
IPL Subsidiary | Maximum
Temporary Equity [Line Items]
Temporary equity, redemption price per share | $ / shares	$ 118	$ 118,000,000
DPL Subsidiary
Temporary Equity [Line Items]
Temporary equity carrying amount	$ 18	$ 18
Number of preferred stock series | series	3
Temporary equity annual dividend requirement	$ 1	$ 1
Number of consecutive quarters without paid dividends to invoke board of directors election rule | quarter		4,000,000
Number of quarters cumulative dividends in arrears to invoke board of directors election rule | quarter	4
DPL Subsidiary | Minimum
Temporary Equity [Line Items]
Temporary equity, redemption price per share | $ / shares	$ 101	$ 101,000,000
DPL Subsidiary | Maximum
Temporary Equity [Line Items]
Temporary equity, redemption price per share | $ / shares	$ 103	$ 103,000,000
IPALCO Enterprises, Inc. [Member]
Temporary Equity [Line Items]
Sale of Stock, Consideration Received Per Transaction	$ 460
Redeemable stock of subsidiaries	83	$ 0
Additional Paid-in Capital [Member] | IPALCO Enterprises, Inc. [Member]
Temporary Equity [Line Items]
Unrealized Gain (Loss) on Investments	$ 377	$ 0