Debt Obligations (Long-term Debt) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended				12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended							12 Months Ended			12 Months Ended					12 Months Ended			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 DP&L [Member]	Dec. 31, 2012 DP&L [Member]	Dec. 31, 2013 First Mortgage Bonds Maturing in October 2013 - 5.125% [Member]	Dec. 31, 2013 First Mortgage Bonds Maturing in October 2013 - 5.125% [Member] DP&L [Member]	Dec. 31, 2013 First Mortgage Bonds Maturing in September 2016 - 1.9%	Sep. 19, 2013 First Mortgage Bonds Maturing in September 2016 - 1.9%	Dec. 31, 2013 First Mortgage Bonds Maturing in September 2016 - 1.9% DP&L [Member]	Sep. 19, 2013 First Mortgage Bonds Maturing in September 2016 - 1.9% DP&L [Member]	Dec. 31, 2013 Pollution Control Series Maturing in January 2028 - 4.70% [Member]	Dec. 31, 2012 Pollution Control Series Maturing in January 2028 - 4.70% [Member]	Dec. 31, 2013 Pollution Control Series Maturing in January 2028 - 4.70% [Member] DP&L [Member]	Dec. 31, 2012 Pollution Control Series Maturing in January 2028 - 4.70% [Member] DP&L [Member]	Dec. 31, 2013 Pollution Control Series Maturing in January 2034 - 4.80% [Member]	Dec. 31, 2012 Pollution Control Series Maturing in January 2034 - 4.80% [Member]	Dec. 31, 2013 Pollution Control Series Maturing in January 2034 - 4.80% [Member] DP&L [Member]	Dec. 31, 2012 Pollution Control Series Maturing in January 2034 - 4.80% [Member] DP&L [Member]	Dec. 31, 2013 Pollution Control Series Maturing in September 2036 - 4.80% [Member]	Dec. 31, 2012 Pollution Control Series Maturing in September 2036 - 4.80% [Member]	Dec. 31, 2013 Pollution Control Series Maturing in September 2036 - 4.80% [Member] DP&L [Member]	Dec. 31, 2012 Pollution Control Series Maturing in September 2036 - 4.80% [Member] DP&L [Member]	Dec. 31, 2013 Pollution control series maturing in November 2040 - variable rates: 0.04% - 0.26% and 0.06% - 0.32% [Member]	Dec. 31, 2012 Pollution control series maturing in November 2040 - variable rates: 0.04% - 0.26% and 0.06% - 0.32% [Member]	Dec. 31, 2013 Pollution control series maturing in November 2040 - variable rates: 0.04% - 0.26% and 0.06% - 0.32% [Member] DP&L [Member]	Dec. 31, 2012 Pollution control series maturing in November 2040 - variable rates: 0.04% - 0.26% and 0.06% - 0.32% [Member] DP&L [Member]	Dec. 31, 2013 U.S. Government note maturing in February 2061 - 4.20% [Member]	Dec. 31, 2012 U.S. Government note maturing in February 2061 - 4.20% [Member]	Mar. 01, 2011 U.S. Government note maturing in February 2061 - 4.20% [Member]	Dec. 31, 2013 U.S. Government note maturing in February 2061 - 4.20% [Member] DP&L [Member]	Dec. 31, 2012 U.S. Government note maturing in February 2061 - 4.20% [Member] DP&L [Member]	Mar. 01, 2011 U.S. Government note maturing in February 2061 - 4.20% [Member] DP&L [Member]	Dec. 31, 2013 Bank Term Loan - variable rates: 2.22% - 2.30% and 1.48% - 4.25% [Member]	Dec. 31, 2012 Bank Term Loan - variable rates: 2.22% - 2.30% and 1.48% - 4.25% [Member]	Dec. 31, 2013 Bank Term Loan maturing in May 2018 [Member]	Dec. 31, 2013 Note to DPL Capital Trust II Maturing in September 2031 - 8.125% [Member]	Dec. 31, 2012 Note to DPL Capital Trust II Maturing in September 2031 - 8.125% [Member]	Dec. 31, 2013 Five Year Senior Unsecured Notes at 6.50% maturing on October 15, 2016 [Member]	Dec. 31, 2012 Five Year Senior Unsecured Notes at 6.50% maturing on October 15, 2016 [Member]	Oct. 03, 2011 Five Year Senior Unsecured Notes at 6.50% maturing on October 15, 2016 [Member]	Dec. 31, 2013 Ten Year Senior Unsecured Notes at 7.25% maturing at October 15, 2021 [Member]	Oct. 03, 2013 Ten Year Senior Unsecured Notes at 7.25% maturing at October 15, 2021 [Member]	Dec. 31, 2012 Ten Year Senior Unsecured Notes at 7.25% maturing at October 15, 2021 [Member]	Oct. 03, 2011 Ten Year Senior Unsecured Notes at 7.25% maturing at October 15, 2021 [Member]
Long-term debt, gross	$ 2,284.2	$ 2,025.0	$ 876.9	$ 332.7			$ 444.3	$ 445.0	$ 445.0	$ 445.0	$ 36.0	$ 36.1	$ 35.3	$ 35.3	$ 179.6	$ 179.6	$ 179.1	$ 179.1	$ 96.4	$ 96.3	$ 100.0	$ 100.0	$ 100.0		$ 100.0		$ 18.3	$ 18.3	$ 18.7	$ 18.2	$ 18.3	$ 18.7		$ 425.0	$ 180.0	$ 19.6	$ 19.6	$ 430.0	$ 450.0		$ 780.0		$ 800.0
Total long-term debt at subsidary	874.6	330.4
Obligation for capital lease		0.1		0.1
Unamortized debt discount			(0.7)	(0.1)
Total long-term debt	$ 2,298.4		$ 877.8
Debt instrument maturity year					Oct. 01, 2013		Sep. 01, 2016		Sep. 01, 2016		Jan. 01, 2028		Jan. 01, 2028		Jan. 01, 2034		Jan. 01, 2034		Sep. 01, 2036		Sep. 01, 2036		Nov. 01, 2040		Nov. 01, 2040		Feb. 01, 2061			Feb. 01, 2061			Aug. 01, 2014		May 01, 2018	Sep. 01, 2031		Oct. 01, 2016			Oct. 01, 2021
Debt instrument interest percentage					5.125%	1.875%	1.875%		1.875%		4.70%		4.70%		4.80%		4.80%		4.80%		4.80%						4.20%		4.20%	4.20%		4.20%			2.42%	8.125%		6.50%		6.50%	7.25%	7.25%		7.25%
Debt instrument interest percentage minimum																							0.05%	0.04%	0.05%	0.04%				4.20%			2.46%	1.48%	2.42%
Debt instrument interest percentage maximum																							0.24%	0.26%	0.24%	0.26%								4.25%	2.45%