Business Segments (Narrative) (Details)	3 Months Ended
	Mar. 31, 2014 sqmi
Service area, square miles	6,000
Number of coal fired power plants	7
Approximate number of retail customers	516,000
Approximate Number Of Competitive Retail Customers	322,000
Electric generation through competitive bid	10.00%
Number of MC Squared Retail Customers	149,000
DP&L [Member]
Service area, square miles	6,000
Number of coal fired power plants	7
Approximate number of retail customers	516,000
Electric generation through competitive bid	10.00%