Pension and Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Schedule of Amounts Recognized in Balance Sheet [Table Text Block]

$ in millions	Pension				Postretirement
	December 31,				December 31,
	2013		2012		2013		2012
Amounts recognized in the Balance sheets
Current liabilities	$	(0.4)	$	(0.4)	$	(0.5)	$	(0.6)
Non-current liabilities		(21.0)		(33.8)		(15.5)		(17.6)
Net liability at Year ended December 31,	$	(21.4)	$	(34.2)	$	(16.0)	$	(18.2)
Amounts recognized in Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities, pre-tax
Components:
Prior service cost	$	8.8	$	10.3	$	0.5	$	0.5
Net actuarial loss / (gain)		63.0		79.9		(6.0)		(4.5)
Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities, pre-tax	$	71.8	$	90.2	$	(5.5)	$	(4.0)
Recorded as:
Regulatory asset	$	76.3	$	88.0	$	-	$	0.5
Regulatory liability		-		-		(5.2)		(5.0)
Accumulated other comprehensive income		(4.5)		2.2		(0.3)		0.5
Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities, pre-tax	$	71.8	$	90.2	$	(5.5)	$	(4.0)

Estimated Amounts that will be Amortized from Accumulated Other Comprehensive Income, Regulatory Assets And Regulatory Liabilities

$ in millions	Pension		Postretirement
Net actuarial gain / (loss)	$	3.4	$	(0.5)
Prior service cost	$	1.5	$	-

Weighted Average Assumptions Used to Determine Benefit Obligations

Benefit Obligation Assumptions	Pension			Postretirement
	2013	2012	2011	2013	2012	2011
Discount rate for obligations	4.86%	4.04%	4.88%	4.58%	3.75%	4.62%
Rate of compensation increases	3.94%	3.94%	3.94%	N/A	N/A	N/A

Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost (Income)

Net Periodic Benefit Cost / (Income) Assumptions	Pension			Postretirement
	2013	2012	2011	2013	2012	2011
Discount rate - Successor	4.04%	4.88%	5.31%	4.58%	4.62%	4.96%
Discount rate - Predecessor			4.88%			4.62%
Expected rate of return on plan assets - Successor	6.75%	7.00%	8.00%	6.00%	6.00%	6.00%
Expected rate of return on plan assets - Predecessor			7.00%			6.00%
Rate of compensation increases	3.94%	3.94%	3.94%	N/A	N/A	N/A

Assumed Health Care Cost Trend Rates

Health Care Cost Assumptions	Expense			Benefit Obligation
	2013	2012	2011	2013	2012	2011
Pre - age 65
Current health care cost trend rate	8.00%	8.50%	8.50%	7.75%	8.00%	8.50%
Year trend reaches ultimate - Successor	2019	2019	2018	2023	2019	2019
Year trend reaches ultimate - Predecessor			2019			2019
Post - age 65
Current health care cost trend rate	7.50%	8.00%	8.00%	6.75%	7.50%	8.00%
Year trend reaches ultimate - Successor	2018	2018	2017	2021	2018	2018
Year trend reaches ultimate - Predecessor			2018			2018
Ultimate health care cost trend rate	5.00%	5.00%	5.00%	5.00%	5.00%	5.00%

Effect of Change in Health Care Cost Trend Rate

Effect of change in health care cost trend rate
$ in millions	One-percent increase		One-percent decrease
Service cost plus interest cost	$	0.1	$	(0.1)
Benefit obligation	$	0.9	$	(0.8)

Estimated Future Benefit Payments and Medicare Part D Reimbursements

Estimated future benefit payments and Medicare Part D reimbursements
$ in millions due within the following years:	Pension		Postretirement
2014	$	25.0	$	2.2
2015	$	23.9	$	2.1
2016	$	23.9	$	2.0
2017	$	24.3	$	1.8
2018	$	24.6	$	1.6
2019 - 2023	$	126.5	$	6.4

DP&L [Member]

Schedule of Amounts Recognized in Balance Sheet [Table Text Block]

$ in millions	Pension				Postretirement
	December 31,				December 31,
	2013		2012		2013		2012
Amounts recognized in the Balance sheets
Current liabilities	$	(0.4)	$	(0.4)	$	(0.5)	$	(0.6)
Non-current liabilities		(21.0)		(33.8)		(15.5)		(17.6)
Net liability at Year ended December 31,	$	(21.4)	$	(34.2)	$	(16.0)	$	(18.2)
Amounts recognized in Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities, pre-tax
Components:
Prior service cost	$	16.3	$	19.0	$	0.7	$	0.8
Net actuarial loss / (gain)		115.1		136.1		(6.9)		(5.7)
Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities, pre-tax	$	131.4	$	155.1	$	(6.2)	$	(4.9)
Recorded as:
Regulatory asset	$	76.3	$	88.0	$	-	$	0.5
Regulatory liability		-		-		(5.2)		(5.0)
Accumulated other comprehensive income		55.1		67.1		(1.0)		(0.4)
Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities, pre-tax	$	131.4	$	155.1	$	(6.2)	$	(4.9)

Estimated Amounts that will be Amortized from Accumulated Other Comprehensive Income, Regulatory Assets And Regulatory Liabilities

$ in millions	Pension		Postretirement
Net actuarial gain / (loss)	$	6.4	$	(0.8)
Prior service cost	$	2.8	$	0.1

Weighted Average Assumptions Used to Determine Benefit Obligations

Benefit Obligation Assumptions	Pension			Postretirement
	2013	2012	2011	2013	2012	2011
Discount rate for obligations	4.86%	4.04%	4.88%	4.58%	3.75%	4.62%
Rate of compensation increases	3.94%	3.94%	3.94%	N/A	N/A	N/A

Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost (Income)

Net Periodic Benefit Cost / (Income) Assumptions	Pension			Postretirement
	2013	2012	2011	2013	2012	2011
Discount rate	4.04%	4.88%	5.31%	4.58%	4.62%	4.96%
Expected rate of return on plan assets	6.75%	7.00%	8.00%	6.00%	6.00%	6.00%
Rate of compensation increases	3.94%	3.94%	3.94%	N/A	N/A	N/A

Assumed Health Care Cost Trend Rates

Health Care Cost Assumptions	Expense			Benefit Obligation
	2013	2012	2011	2013	2012	2011
Pre - age 65
Current health care cost trend rate	8.00%	8.50%	8.50%	7.75%	8.00%	8.50%
Year trend reaches ultimate	2019	2019	2018	2023	2019	2019
Post - age 65
Current health care cost trend rate	7.50%	8.00%	8.00%	6.75%	7.50%	8.00%
Year trend reaches ultimate	2018	2018	2017	2021	2018	2018
Ultimate health care cost trend rate	5.00%	5.00%	5.00%	5.00%	5.00%	5.00%

Effect of Change in Health Care Cost Trend Rate

Effect of change in health care cost trend rate
$ in millions	One-percent increase		One-percent decrease
Service cost plus interest cost	$	0.1	$	(0.1)
Benefit obligation	$	0.9	$	(0.8)

Estimated Future Benefit Payments and Medicare Part D Reimbursements

Estimated future benefit payments and Medicare Part D reimbursements
$ in millions due within the following years:	Pension		Postretirement
2014	$	25.0	$	2.2
2015	$	23.9	$	2.1
2016	$	23.9	$	2.0
2017	$	24.3	$	1.8
2018	$	24.6	$	1.6
2019 - 2023	$	126.5	$	6.7

Fair Value Measurements for Plan Assets

Fair Value Measurements for Pension Plan Assets at December 31, 2013
Asset Category $ in millions	Market Value at December 31, 2013		Quoted prices in active markets for identical assets		Significant observable inputs		Significant unobservable inputs
				(Level 1)		(Level 2)		(Level 3)
Equity securities (a)
Small/Mid cap equity	$	10.5	$	10.5	$	-	$	-
Large cap equity		20.8		20.8		-		-
International equity		20.3		20.3		-		-
Emerging markets equity		3.2		3.2		-		-
SIIT dynamic equity		10.5		10.5		-		-
Total equity securities		65.3		65.3		-		-
Debt Securities (b)
Emerging markets debt		6.6		6.6		-		-
High yield bond		6.9		6.9		-		-
Long duration fund		223.3		223.3		-		-
Total debt securities		236.8		236.8		-		-
Cash and cash equivalents (c)
Cash		0.9		0.9		-		-
Other investments (d)
Core property collective fund		23.5		-		23.5		-
Common collective fund		22.6		-		22.6		-
Total other investments		46.1		-		46.1		-
Total pension plan assets	$	349.1	$	303.0	$	46.1	$	-

Fair Value Measurements for Pension Plan Assets at December 31, 2012
Asset Category $ in millions	Market Value at December 31, 2012		Quoted prices in active markets for identical assets		Significant observable inputs		Significant unobservable inputs
				(Level 1)		(Level 2)		(Level 3)
Equity securities (a)
Small/Mid cap equity	$	14.3	$	14.3	$	-	$	-
Large cap equity		50.5		50.5		-		-
International equity		37.0		37.0		-		-
Total equity securities		101.8		101.8		-		-
Debt Securities (b)
Emerging markets debt		7.4		7.4		-		-
High yield bond		12.7		12.7		-		-
Long duration fund		188.6		188.6		-		-
Total debt securities		208.7		208.7		-		-
Cash and cash equivalents (c)
Cash		13.9		13.9		-		-
Other investments (d)
Limited partnership interest		-		-		-		-
Common collective fund		37.0		-		37.0		-
Total other investments		37.0		-		37.0		-
Total pension plan assets	$	361.4	$	324.4	$	37.0	$	-

Pension [Member]

Pension And Postretirement Benefit Plans' Obligations And Assets

$ in millions	Pension
	Year ended December 31, 2013		Year ended December 31, 2012
Change in benefit obligation
Benefit obligation at beginning of period	$	395.6	$	365.2
Service cost		7.2		6.2
Interest cost		15.6		17.3
Plan amendments		-		-
Actuarial (gain) / loss		(26.5)		29.1
Benefits paid		(21.4)		(22.2)
Benefit obligation at end of period		370.5		395.6
Change in plan assets
Fair value of plan assets at beginning of period		361.4		335.9
Actual return on plan assets		8.7		46.2
Contributions to plan assets		0.4		1.5
Benefits paid		(21.4)		(22.2)
Fair value of plan assets at end of period		349.1		361.4
Funded status of plan	$	(21.4)	$	(34.2)

Net Periodic Benefit Cost / (Income)

Net Periodic Benefit Cost - Pension	Successor						Predecessor
$ in millions	Year ended December 31, 2013		Year ended December 31, 2012		November 28, 2011 through December 31, 2011		January 1, 2011 through November 27, 2011
Service cost	$	7.2	$	6.2	$	0.5	$	4.5
Interest cost		15.6		17.3		1.5		15.5
Expected return on assets (a)		(23.3)		(22.7)		(2.0)		(22.5)
Amortization of unrecognized:
Actuarial gain		4.9		5.0		0.4		7.6
Prior service cost		1.5		1.5		0.1		2.0
Net periodic benefit cost before adjustments	$	5.9	$	7.3	$	0.5	$	7.1

Other Changes in Plan Assets and Benefit Obligation Recognized in Accumulated Other Comprehensive Income, Regulatory Assets And Regulatory Liabilities

Pension	Successor						Predecessor
$ in millions	Year ended December 31, 2013		Year ended December 31, 2012		November 28, 2011 through December 31, 2011		January 1, 2011 through November 27, 2011
Net actuarial loss / (gain)	$	(12.0)	$	5.5	$	-	$	(38.7)
Prior service credit		-		-		-		(2.2)
Reversal of amortization item:
Net actuarial loss		(4.9)		(5.0)		(0.4)		(7.6)
Prior service cost		(1.5)		(1.5)		(0.1)		(2.0)
Total recognized in Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities	$	(18.4)	$	(1.0)	$	(0.5)	$	(50.5)
Total recognized in net periodic benefit cost Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities	$	(12.5)	$	6.3	$	(0.5)	$	(43.4)

Fair Value Measurements for Plan Assets

Fair Value Measurements for Pension Plan Assets at December 31, 2013
Asset Category $ in millions	Market Value at December 31, 2013		Quoted prices in active markets for identical assets		Significant observable inputs		Significant unobservable inputs
				(Level 1)		(Level 2)		(Level 3)
Equity securities (a)
Small/Mid cap equity	$	10.5	$	10.5	$	-	$	-
Large cap equity		20.8		20.8		-		-
International equity		20.3		20.3		-		-
Emerging markets equity		3.2		3.2		-		-
SIIT dynamic equity		10.5		10.5		-		-
Total equity securities		65.3		65.3		-		-
Debt securities (b)
Emerging markets debt		6.6		6.6		-		-
High yield bond		6.9		6.9		-		-
Long duration fund		223.3		223.3		-		-
Total debt securities		236.8		236.8		-		-
Cash and cash equivalents (c)
Cash		0.9		0.9		-		-
Other investments (d)
Core property collective fund		23.5		-		23.5		-
Common collective fund		22.6		-		22.6		-
Total other investments		46.1		-		46.1		-
Total pension plan assets	$	349.1	$	303.0	$	46.1	$	-

Fair Value Measurements for Pension Plan Assets at December 31, 2012
Asset Category $ in millions	Market Value at December 31, 2012		Quoted prices in active markets for identical assets		Significant observable inputs		Significant unobservable inputs
				(Level 1)		(Level 2)		(Level 3)
Equity securities (a)
Small/Mid cap equity	$	14.3	$	14.3	$	-	$	-
Large cap equity		50.5		50.5		-		-
International equity		37.0		37.0		-		-
Total equity securities		101.8		101.8		-		-
Debt securities (b)
Emerging markets debt		7.4		7.4		-		-
High yield bond		12.7		12.7		-		-
Long duration fund		188.6		188.6		-		-
Total debt securities		208.7		208.7		-		-
Cash and cash equivalents (c)
Cash		13.9		13.9		-		-
Other investments (d)
Limited partnership interest		-		-		-		-
Common collective fund		37.0		-		37.0		-
Total other investments		37.0		-		37.0		-
Total pension plan assets	$	361.4	$	324.4	$	37.0	$	-

Pension [Member] | DP&L [Member]

Pension And Postretirement Benefit Plans' Obligations And Assets

$ in millions	Pension
	Years ended December 31,
	2013		2012
Change in benefit obligation
Benefit obligation at beginning of period	$	395.6	$	365.2
Service cost		7.2		6.2
Interest cost		15.6		17.3
Plan amendments		-		-
Actuarial (gain) / loss		(26.5)		29.1
Benefits paid		(21.4)		(22.2)
Benefit obligation at end of period		370.5		395.6
Change in plan assets
Fair value of plan assets at beginning of period		361.4		335.9
Actual return on plan assets		8.7		46.2
Contributions to plan assets		0.4		1.5
Benefits paid		(21.4)		(22.2)
Fair value of plan assets at end of period		349.1		361.4
Funded status of plan	$	(21.4)	$	(34.2)

Net Periodic Benefit Cost / (Income)

Net Periodic Benefit Cost - Pension
	Years ended December 31,
$ in millions	2013		2012		2011
Service cost	$	7.2	$	6.2	$	5.0
Interest cost		15.6		17.3		17.0
Expected return on assets (a)		(23.6)		(22.7)		(24.5)
Amortization of unrecognized:
Actuarial gain		9.3		8.8		8.0
Prior service cost		2.8		2.8		2.1
Net periodic benefit cost before adjustments		11.3		12.4		7.6
Settlement Expense		-		0.6		-
Net periodic benefit cost after adjustments	$	11.3	$	13.0	$	7.6

Other Changes in Plan Assets and Benefit Obligation Recognized in Accumulated Other Comprehensive Income, Regulatory Assets And Regulatory Liabilities

Pension
	Years ended December 31,
$ in millions	2013		2012		2011
Net actuarial loss / (gain)	$	(11.7)	$	5.2	$	22.8
Prior service cost		-		-		7.1
Reversal of amortization item:
Net actuarial loss		(9.3)		(9.4)		(8.0)
Prior service cost		(2.8)		(2.8)		(2.0)
Transition asset		-		-		-
Total recognized in Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities	$	(23.8)	$	(7.0)	$	19.9
Total recognized in net periodic benefit cost Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities	$	(12.5)	$	6.0	$	27.5

Postretirement [Member]

Pension And Postretirement Benefit Plans' Obligations And Assets

$ in millions	Postretirement
	Year ended December 31, 2013		Year ended December 31, 2012
Change in benefit obligation
Benefit obligation at beginning of period	$	22.4	$	21.7
Service cost		0.2		0.1
Interest cost		0.8		0.9
Actuarial (gain) / loss		(2.2)		1.2
Benefits paid		(1.5)		(1.7)
Medicare Part D reimbursement		-		0.2
Benefit obligation at end of period		19.7		22.4
Change in plan assets
Fair value of plan assets at beginning of period		4.2		4.5
Actual return on plan assets		-		0.2
Contributions to plan assets		1.0		1.2
Benefits paid		(1.5)		(1.7)
Fair value of plan assets at end of period		3.7		4.2
Funded status of plan	$	(16.0)	$	(18.2)

Net Periodic Benefit Cost / (Income)

Net Periodic Benefit Cost / (Income) - Postretirement	Successor						Predecessor
$ in millions	Year ended December 31, 2013		Year ended December 31, 2012		November 28, 2011 through December 31, 2011		January 1, 2011 through November 27, 2011
Service cost	$	0.2	$	0.1	$	-	$	0.1
Interest cost		0.8		0.9		0.1		0.9
Expected return on assets (a)		(0.1)		(0.3)		-		(0.3)
Amortization of unrecognized:
Actuarial loss		(0.5)		(0.6)		-		(1.0)
Prior service cost		-		-		(0.1)		0.1
Net periodic benefit cost / (income) before adjustments	$	0.4	$	0.1	$	-	$	(0.2)

Other Changes in Plan Assets and Benefit Obligation Recognized in Accumulated Other Comprehensive Income, Regulatory Assets And Regulatory Liabilities

Postretirement	Successor						Predecessor
$ in millions	Year ended December 31, 2013		Year ended December 31, 2012		November 28, 2011 through December 31, 2011		January 1, 2011 through November 27, 2011
Net actuarial loss / (gain)	$	(2.0)	$	1.0	$	-	$	0.2
Prior service cost / (credit)		-		-		0.1		(0.1)
Reversal of amortization item:
Net actuarial gain		0.5		0.7		-		1.0
Prior service cost		-		-		-		(0.1)
Transition asset		-		-		(0.1)		-
Total recognized in Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities	$	(1.5)	$	1.7	$	-	$	1.0
Total recognized in net periodic benefit cost and Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities	$	(1.1)	$	1.8	$	-	$	0.8

Fair Value Measurements for Plan Assets

Fair Value Measurements for Pension Plan Assets at December 31, 2013
Asset Category $ in millions	Market Value at December 31, 2013		Quoted prices in active markets for identical assets		Significant observable inputs		Significant unobservable inputs
				(Level 1)		(Level 2)		(Level 3)
JP Morgan Core Bond Fund (a)	$	3.7	$	3.7	$	-	$	-

Fair Value Measurements for Pension Plan Assets at December 31, 2012
Asset Category $ in millions	Market Value at December 31, 2012		Quoted prices in active markets for identical assets		Significant observable inputs		Significant unobservable inputs
				(Level 1)		(Level 2)		(Level 3)
JP Morgan Core Bond Fund (a)	$	4.2	$	4.2	$	-	$	-

Postretirement [Member] | DP&L [Member]

Pension And Postretirement Benefit Plans' Obligations And Assets

$ in millions	Postretirement
	Years ended December 31,
	2013		2012
Change in benefit obligation
Benefit obligation at beginning of period	$	22.4	$	21.7
Service cost		0.2		0.1
Interest cost		0.8		0.9
Actuarial (gain) / loss		(2.2)		1.2
Benefits paid		(1.5)		(1.7)
Medicare Part D reimbursement		-		0.2
Benefit obligation at end of period		19.7		22.4
Change in plan assets
Fair value of plan assets at beginning of period		4.2		4.5
Actual return on plan assets		-		0.2
Contributions to plan assets		1.0		1.2
Benefits paid		(1.5)		(1.7)
Fair value of plan assets at end of period		3.7		4.2
Funded status of plan	$	(16.0)	$	(18.2)

Net Periodic Benefit Cost / (Income)

Net Periodic Benefit Cost / (Income) - Postretirement
	Years ended December 31,
$ in millions	2013		2012		2011
Service cost	$	0.2	$	0.1	$	0.1
Interest cost		0.8		0.9		1.0
Expected return on assets		(0.2)		(0.3)		(0.3)
Amortization of unrecognized:
Actuarial loss		(0.7)		(0.9)		(1.1)
Prior service credit		0.1		0.1		0.1
Net periodic benefit cost / (income) before adjustments	$	0.2	$	(0.1)	$	(0.2)

Other Changes in Plan Assets and Benefit Obligation Recognized in Accumulated Other Comprehensive Income, Regulatory Assets And Regulatory Liabilities

Postretirement
	Years ended December 31,
$ in millions	2013		2012		2011
Net actuarial loss / (gain)	$	(1.9)	$	1.1	$	(1.3)
Prior service credit		-		-		-
Reversal of amortization item:
Net actuarial gain		0.7		0.9		1.2
Prior service credit		(0.1)		(0.1)		(0.1)
Transition asset		-		-		-
Total recognized in Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities	$	(1.3)	$	1.9	$	(0.2)
Total recognized in net periodic benefit cost and Accumulated Other Comprehensive Income, Regulatory Assets and Regulatory Liabilities	$	(1.1)	$	1.8	$	(0.4)

Fair Value Measurements for Plan Assets

Fair Value Measurements for Pension Plan Assets at December 31, 2013
Asset Category $ in millions	Market Value at December 31, 2013		Quoted prices in active markets for identical assets		Significant observable inputs		Significant unobservable inputs
				(Level 1)		(Level 2)		(Level 3)
JP Morgan Core Bond Fund (a)	$	3.7	$	3.7	$	-	$	-

Fair Value Measurements for Pension Plan Assets at December 31, 2012
Asset Category $ in millions	Market Value at December 31, 2012		Quoted prices in active markets for identical assets		Significant observable inputs		Significant unobservable inputs
				(Level 1)		(Level 2)		(Level 3)
JP Morgan Core Bond Fund (a)	$	4.2	$	4.2	$	-	$	-