Debt Obligations (Narrative) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended							6 Months Ended					6 Months Ended				6 Months Ended	4 Months Ended			6 Months Ended			6 Months Ended		6 Months Ended		6 Months Ended				6 Months Ended		6 Months Ended		6 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014 DP&L [Member]	Mar. 31, 2014 DP&L [Member]	Dec. 31, 2013 DP&L [Member]	Dec. 04, 2008 DP&L [Member]	Jun. 30, 2014 DPL [Member] Credit Facility [Member]	Jun. 30, 2014 DPL [Member] Other Debt [Member]	Jun. 30, 2014 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]	Mar. 01, 2011 U.S. Government note maturing in February 2061 - 4.20% [Member]	Jun. 30, 2014 U.S. Government note maturing in February 2061 - 4.20% [Member] DP&L [Member]	Dec. 31, 2013 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]	Mar. 31, 2014 Related Party Notes Payable [Member]	Jun. 30, 2014 Revolving Credit Agreeement with Bank Group Expiring 2018 [Member]	May 10, 2013 Revolving Credit Agreeement with Bank Group Expiring 2018 [Member] DP&L [Member]	Jun. 30, 2014 Revolving Credit Agreeement with Bank Group Expiring 2018 [Member] DP&L [Member]	Sep. 30, 2013 Revolving Credit Agreeement with Bank Group Expiring 2018 [Member] DP&L [Member]	Jun. 30, 2014 Revolving Credit Agreeement with Bank Group Expiring 2018 [Member] DPL [Member]	Jun. 30, 2014 Five Year Senior Unsecured Notes at 6.50% maturing on October 15, 2016 [Member]	Dec. 31, 2013 Five Year Senior Unsecured Notes at 6.50% maturing on October 15, 2016 [Member]	Jun. 30, 2014 Ten Year Senior Unsecured Notes at 7.25% maturing at October 15, 2021 [Member]	Dec. 31, 2013 Ten Year Senior Unsecured Notes at 7.25% maturing at October 15, 2021 [Member]	Jun. 30, 2014 First Mortgage Bonds Maturing in September 2016	Dec. 31, 2013 First Mortgage Bonds Maturing in September 2016	Jun. 30, 2014 First Mortgage Bonds Maturing in September 2016 DP&L [Member]	Dec. 31, 2013 First Mortgage Bonds Maturing in September 2016 DP&L [Member]	Sep. 30, 2013 First Mortgage Bonds Maturing in September 2016 DP&L [Member]	Jun. 30, 2014 First Mortgage Bonds Maturing in September 2016 DPL [Member]	Jun. 30, 2014 Note to DPL Capital Trust II Maturing in September 2031 - 8.125% [Member]	Dec. 31, 2013 Note to DPL Capital Trust II Maturing in September 2031 - 8.125% [Member]	Jun. 30, 2014 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]	Jun. 30, 2014 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 Pollution control series maturing in November 2040 - variable rates: 0.04% - 0.26% and 0.06% - 0.32% [Member] DP&L [Member]	Jun. 30, 2014 Bank Term Loan maturing in May 2018 [Member]	Dec. 31, 2013 Bank Term Loan maturing in May 2018 [Member]
Additional principal amount of senior notes to be raised	$ 1,250.0																					$ 450.0		$ 800.0
Debt Instrument, Maturity Date Range, End										Feb. 01, 2061			Feb. 01, 2061									Oct. 01, 2016		Oct. 01, 2021		Sep. 01, 2016		Sep. 01, 2016				Sep. 01, 2031		Nov. 01, 2040		Nov. 01, 2040		May 01, 2018
Notes Payable, Related Parties					15.0
Unsecured revolving credit agreement																		300.0	300.0		100.0
Withdrawals from revolving credit facilities	115.0	50.0
Increase/decrease additional facility																	100.0	100.0			100.0
Letter of credit sublimit																	100.0	100.0			100.0
Letters of credit outstanding																			0.7	0.7
Collateralized debt	100.0						100.0
Line of Credit Facility, Remaining Borrowing Capacity																			299.3	299.3
Long-term Debt, Gross										(18.2)	(18.3)		18.2	18.2	18.7							430.0	430.0	780.0	780.0	445.0	445.0	445.0	445.0	445.0		19.7	19.6	100.0	100.0	100.0	100.0	160.0	180.0
Premium Expenses																						1.9		0.5
Current portion - long-term debt	30.1		10.2	0.1		0.2
Term Loan Amortization Year 1																															5.00%
Repayments of debt								$ 50.0	$ 200.0													$ 20.0		$ 20.0
Debt instrument interest percentage										4.20%		4.20%	4.20%		4.20%	2.00%						6.50%		7.25%		1.875%		1.875%				8.125%