Equity Equity - Net Income (Loss) Attributable to The AES Corporation (Details) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Net Income (Loss) Attributable to Parent	$ 128	$ 101	$ 290	$ 684	$ (1,342)	$ 152	$ 53	$ (24)		$ 1,203	$ (1,161)	$ (1,130)
Transfers from the noncontrolling interest:
Net transfers (to) from noncontrolling interest										(3)	253	(2)
Change from net income (loss) attributable to The AES Corporation and transfers (to) from noncontrolling interests										1,200	(908)	(1,132)
Additional Paid-in Capital [Member]
Transfers from the noncontrolling interest:
Increase (decrease) in The AES Corporation's paid-in capital for sale of subsidiary shares										(3)	13	84
Increase (decrease) in The AES Corporation's paid-in-capital for purchase of subsidiary shares										0	(240)	2
Retained Earnings [Member]
Transfers from the noncontrolling interest:
Increase (decrease) in The AES Corporation's paid-in-capital for purchase of subsidiary shares											0	0
IPALCO Enterprises, Inc. [Member] | Retained Earnings [Member]
Transfers from the noncontrolling interest:
Increase (decrease) in The AES Corporation's paid-in capital for sale of subsidiary shares									$ 84	$ 0	$ 0	$ (84)