Supplemental Financial Information (Accumulated Other Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	11 Months Ended	12 Months Ended			12 Months Ended								12 Months Ended			12 Months Ended			12 Months Ended			12 Months Ended
	Nov. 27, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 DP&L [Member]	Dec. 31, 2012 DP&L [Member]	Dec. 31, 2011 DP&L [Member]	Dec. 31, 2013 Available-for-sale Securities [Member]	Dec. 31, 2012 Available-for-sale Securities [Member]	Dec. 31, 2013 Available-for-sale Securities [Member] DP&L [Member]	Dec. 31, 2012 Available-for-sale Securities [Member] DP&L [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] DP&L [Member]	Dec. 31, 2013 Derivative [Member]	Dec. 31, 2012 Derivative [Member]	Dec. 31, 2011 Derivative [Member]	Dec. 31, 2013 Derivative [Member] DP&L [Member]	Dec. 31, 2012 Derivative [Member] DP&L [Member]	Dec. 31, 2011 Derivative [Member] DP&L [Member]	Dec. 31, 2013 Other Pension Plan, Defined Benefit [Member]	Dec. 31, 2012 Other Pension Plan, Defined Benefit [Member]	Dec. 31, 2011 Other Pension Plan, Defined Benefit [Member]	Dec. 31, 2013 Other Pension Plan, Defined Benefit [Member] DP&L [Member]	Dec. 31, 2012 Other Pension Plan, Defined Benefit [Member] DP&L [Member]	Dec. 31, 2011 Other Pension Plan, Defined Benefit [Member] DP&L [Member]
Total Reclassifications out of AOCI	$ 2.5	$ 5.1	$ (0.6)		$ 7.8	$ (0.8)	$ 2.1	$ 1.4	$ (0.1)	$ 1.4	$ (0.1)		$ 3.4	$ (0.5)		$ 2.6	$ (3.4)		$ 0.3			$ 3.8	$ 2.7
Total Adjustments to AOCI		23.4	(2.9)		4.2	(3.2)		(1.2)	0.5	(1.6)	0.5		19.7	(1.5)		1.0	(3.0)		4.9	(1.9)		4.8	(0.7)
Other Comprehensive Income (Loss), Net of Tax		28.5	(3.5)		12.0	(4.0)		0.2	0.4	(0.2)	0.4		23.1	(2.0)		3.6	(6.4)		5.2	(1.9)		8.6	2.0
Accumulated Other Comprehensive Income (Loss), Net of Tax		$ 24.6	$ (3.9)	$ (0.4)	$ (26.7)	$ (38.7)	$ (34.7)	$ 0.6	$ 0.4	$ 0.8	$ 1.0	$ 0.6	$ 20.6	$ (2.5)	$ (0.5)	$ 6.2	$ 2.6	$ 9.0	$ 3.4	$ (1.8)	$ 0.1	$ (33.7)	$ (42.3)	$ (44.3)