Goodwill (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Goodwill [Roll Forward]
Goodwill	$ 17,214	$ 17,211
Accumulated impairment charges	(871)	(871)
Foreign exchange and other changes	3
Goodwill as adjusted for accumulated impairment charges	16,343	16,340
Regulated Utilities [Member]
Goodwill [Roll Forward]
Goodwill	15,950	15,950
Accumulated impairment charges
Foreign exchange and other changes
Goodwill as adjusted for accumulated impairment charges	15,950	15,950
International [Member]
Goodwill [Roll Forward]
Goodwill	329	326
Accumulated impairment charges
Foreign exchange and other changes	3
Goodwill as adjusted for accumulated impairment charges	329	326
Commercial Power [Member]
Goodwill [Roll Forward]
Goodwill	935	935
Accumulated impairment charges	(871)	(871)
Foreign exchange and other changes
Goodwill as adjusted for accumulated impairment charges	64	64
Duke Energy Ohio [Member]
Goodwill [Roll Forward]
Goodwill	2,324	2,324
Accumulated impairment charges	(1,404)	(1,404)
Goodwill as adjusted for accumulated impairment charges	920	920
Duke Energy Ohio [Member] | Regulated Utility [Member]
Goodwill [Roll Forward]
Goodwill	1,136	1,136
Accumulated impairment charges	(216)	(216)
Goodwill as adjusted for accumulated impairment charges	920	920
Duke Energy Ohio [Member] | DEO Commercial Power [Member]
Goodwill [Roll Forward]
Goodwill	1,188	1,188
Accumulated impairment charges	(1,188)	(1,188)
Goodwill as adjusted for accumulated impairment charges	$ 0	$ 0