Business Segments (Narrative) (Details)	6 Months Ended
	Jun. 30, 2014 sqmi
Service area, square miles	6,000
Number of coal fired power plants	7
Approximate number of retail customers	515,000
Approximate Number Of Competitive Retail Customers	310,000
Electric generation through competitive bid	10.00%
Number of MC Squared Retail Customers	143,000
DP&L [Member]
Service area, square miles	6,000
Number of coal fired power plants	7
Approximate number of retail customers	515,000
Electric generation through competitive bid	10.00%
Year 2014 [Member]
Electric generation through competitive bid	10.00%
Year 2015 [Member]
Electric generation through competitive bid	60.00%
Year 2016 [Member]
Electric generation through competitive bid	100.00%