Contractual Obligations, Commercial Commitments And Contingencies (Narrative) (Details) (USD $)	12 Months Ended				12 Months Ended					12 Months Ended							12 Months Ended																				12 Months Ended
	Dec. 31, 2012 T	Dec. 31, 2010	Dec. 31, 2011	Nov. 27, 2011	Dec. 31, 2012 DP&L [Member] T	Dec. 31, 2011 DP&L [Member]	Dec. 31, 2010 DP&L [Member]	Dec. 31, 2012 DPLE and DPLER [Member]	Dec. 31, 2012 MC Squared [Member]	Dec. 31, 2012 Beckjord Unit 6 [Member]	Dec. 31, 2012 Beckjord Unit 6 [Member] DP&L [Member]	Dec. 31, 2012 Hutchings Plant [Member]	Dec. 31, 2012 Hutchings Plant [Member] DP&L [Member]	Dec. 31, 2012 Coal Supply Agreements [Member] T	Dec. 31, 2012 Coal Supply Agreements [Member] DP&L [Member] T	Dec. 31, 2012 Debt Obligation on 4.9% Equity Ownership [Member]	Dec. 31, 2012 Debt Obligation on 4.9% Equity Ownership [Member] DP&L [Member]	Dec. 31, 2012 First Mortgage Bonds Maturing in October 2013 - 5.125% [Member]	Dec. 31, 2012 First Mortgage Bonds Maturing in October 2013 - 5.125% [Member] DP&L [Member]	Dec. 31, 2012 Pollution Control Series Maturing in January 2028 - 4.70% [Member]	Dec. 31, 2012 Pollution Control Series Maturing in January 2028 - 4.70% [Member] DP&L [Member]	Dec. 31, 2012 Pollution Control Series Maturing in January 2034 - 4.80% [Member]	Dec. 31, 2012 Pollution Control Series Maturing in January 2034 - 4.80% [Member] DP&L [Member]	Dec. 31, 2012 Pollution Control Series Maturing in September 2036 - 4.80% [Member]	Dec. 31, 2012 Pollution Control Series Maturing in September 2036 - 4.80% [Member] DP&L [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, 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, 2012 Note to DPL Capital Trust II Maturing in September 2031 - 8.125% [Member]	Feb. 23, 2011 Note to DPL Capital Trust II Maturing in September 2031 - 8.125% [Member]	Sep. 01, 2011 Senior Notes Maturing in September 2011 - 6.875% [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, 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]	Dec. 31, 2012 NOx [Member]	Dec. 31, 2012 NOx [Member] DP&L [Member]	Dec. 31, 2012 SO2 [Member]	Dec. 31, 2012 SO2 [Member] DP&L [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Third party guarantees	$ 21,500,000							$ 21,200,000	$ 300,000
Due to third parties, current	0		100,000
Equity ownership interest					4.90%											4.90%	4.90%
Equity ownership interest aggregate cost																	78,200,000
Debt obligation																1,596,500,000
Long Term Debt Date Range Equity Ownership, Start																	2013
Long Term Debt Date Range Equity Ownership, End																	2040
Debt instrument interest percentage				6.875%														5.125%	5.125%	4.70%	4.70%	4.80%	4.80%	4.80%	4.80%	4.20%	4.20%	4.20%	4.20%	8.125%	8.125%	6.875%	6.50%	6.50%	7.25%	7.25%
Environmental reserves	3,600,000				3,600,000
Unrecognized tax benefit	18,300,000		25,000,000	24,900,000	18,300,000	25,000,000	19,400,000
Percentage of coal-fire power plant holdings	97.00%									50.00%	50.00%	100.00%	100.00%
Percentage of energy generated by coal					97.00%
Emission Reductions																																					73.00%	73.00%	54.00%	54.00%
Annual CO2 emissions generation at stations, in tons	16,000,000				16,000,000
Number of Auxiliary Boilers					7
Number of diesel electric generating engines	18
Number of emergency black start engines	8
Relief and civil penalties, per day	27,500				27,500
Coal supply failure by suppliers														1,500,000	1,500,000
Coal supply agreement, in tons														570,000	570,000,000
Proceeds from Legal Settlements	14,600,000
Proceeds from insurance settlement, operating activities		3,400,000			14,600,000
Interest and Other Income	$ 1,800,000				$ 1,800,000