Debt Obligations (Narrative) (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	3 Months Ended						0 Months Ended		3 Months Ended		3 Months Ended				0 Months Ended	4 Months Ended			0 Months Ended		1 Months Ended	3 Months Ended	0 Months Ended	1 Months Ended	3 Months Ended				3 Months Ended				3 Months Ended		3 Months Ended		3 Months Ended				3 Months Ended
	Oct. 03, 2011	Mar. 31, 2014	Dec. 31, 2013	Dec. 08, 2008	Mar. 31, 2014 DP&L [Member]	Dec. 31, 2013 DP&L [Member]	Dec. 04, 2008 DP&L [Member]	May 10, 2013 DPL [Member] Credit Facility [Member]	May 10, 2013 DPL [Member] Other Debt [Member]	Mar. 31, 2014 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]	Mar. 31, 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]	May 10, 2013 Revolving Credit Agreeement with Bank Group Expiring 2018 [Member]	May 10, 2013 Revolving Credit Agreeement with Bank Group Expiring 2018 [Member] DP&L [Member]	Mar. 31, 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]	May 10, 2013 Revolving Credit Agreeement with Bank Group Expiring 2018 [Member] DPL [Member]	Oct. 03, 2011 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]	Mar. 31, 2014 Five Year Senior Unsecured Notes at 6.50% maturing on October 15, 2016 [Member]	Oct. 03, 2011 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]	Mar. 31, 2014 Ten Year Senior Unsecured Notes at 7.25% maturing at October 15, 2021 [Member]	Mar. 31, 2014 First Mortgage Bonds Maturing in September 2016	Dec. 31, 2013 First Mortgage Bonds Maturing in September 2016	Sep. 13, 2013 First Mortgage Bonds Maturing in September 2016	Mar. 31, 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]	May 10, 2013 First Mortgage Bonds Maturing in September 2016 DPL [Member]	Mar. 31, 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]	Mar. 31, 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]	Mar. 31, 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]		Mar. 31, 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			100.0
Withdrawals from revolving credit facilities		65.0
Increase/decrease additional facility																100.0	100.0			100.0
Letter of credit sublimit																100.0	100.0			100.0
Letters of credit outstanding																		0.4	0.4
Collateralized debt				100.0			100.0
Line of Credit Facility, Remaining Borrowing Capacity																		299.6	299.6
Long-term Debt, Gross											18.7	18.2	18.2	18.7								430.0	430.0		780.0	780.0	444.4	444.3	445.0	445.0	445.0	445.0		19.6	19.6	100.0	100.0	100.0	[1]	100.0	[1]	170.0	180.0
Premium Expenses																						1.9			0.5
Current portion - long-term debt		20.2	10.2		0.2	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%		6.50%	7.25%		7.25%	1.88%			1.875%				8.125%

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