Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2014

Related Party Transactions [Member]

Schedule of Related Party Transactions [Table Text Block]

	Three months ended				Six months ended
	June 30,				June 30,
$ in millions	2014		2013		2014		2013
Transactions with the Service Company
Charges for services provided	$	9.1	$	-	$	22.3	$	-

Related Party Balances [Member]

Schedule of Related Party Transactions [Table Text Block]

Transactions with the Service Company	At June 30, 2014		At December 31, 2013
Net payable to the Service Company	$	(2.0)	$	-

DP&L [Member] | Related Party Transactions [Member]

Schedule of Related Party Transactions [Table Text Block]

	Three months ended				Six months ended
	June 30,				June 30,
$ in millions	2014		2013		2014		2013
DP&L Revenues:
Sales to DPLER (a)	$	83.0	$	81.3	$	190.7	$	160.0
Sales to MC Squared (b)	$	27.0	$	26.8	$	58.0	$	52.4
DP&L Operations and Maintenance Expenses:
Premiums paid for insurance services provided by MVIC (c)	$	(0.7)	$	(0.7)	$	(1.4)	$	(1.4)
Expense recoveries for services provided to DPLER (d)	$	1.1	$	1.4	$	1.1	$	2.5
Transactions with the Service Company
Charges for services provided	$	7.7	$	-	$	19.1	$	-

DP&L [Member] | Related Party Balances [Member]

Schedule of Related Party Transactions [Table Text Block]

DP&L Customer security deposits:	At June 30, 2014		At December 31, 2013
Deposits received from DPLER (e)	$	19.2	$	19.2
Balances with the Service Company (f)
Net payable to the Service Company	$	(2.0)	$	-