Derivative Instruments and Hedging Activities (Tables)

3 Months Ended

9 Months Ended

12 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Schedule of Notional Amounts of Outstanding Derivative Positions

Commodity	Accounting Treatment		Unit	Purchases (in thousands)		Sales (in thousands)		Net Purchases/ (Sales) (in thousands)
FTRs		Mark to Market	MWh		17.4		-		17.4
Heating oil futures		Mark to Market	Gallons		672.0		-		672.0
Forward power contracts		Cash Flow Hedge	MWh		40.7		(3,543.0)		(3,502.3)
Forward power contracts		Mark to Market	MWh		2,320.0		(3,357.9)		(1,037.9)

Commodity	Accounting Treatment		Unit	Purchases (in thousands)		Sales (in thousands)		Net Purchases/ (Sales) (in thousands)
FTRs		Mark to Market	MWh		7.1		-		7.1
Heating oil futures		Mark to Market	Gallons		1,428.0		-		1,428.0
Forward power contracts		Cash Flow Hedge	MWh		140.4		(4,705.7)		(4,565.3)
Forward power contracts		Mark to Market	MWh		3,177.8		(2,883.1)		294.7

Gains or Losses Recognized in AOCI for the Cash Flow Hedges

	Three months ended				Three months ended
	September 30, 2014				September 30, 2013
			Interest				Interest
$ in millions (net of tax)	Power		Rate Hedge		Power		Rate Hedge
Beginning accumulated derivative gain / (loss) in AOCI	$	(12.4)	$	18.8	$	(1.1)	$	12.8
Net gains / (losses) associated with current period hedging transactions		1.2		-		(0.2)		6.4
Net gains / (losses) reclassified to earnings
Interest expense		-		(0.2)		-		-
Revenues		3.4		-		0.3		-
Purchased power		0.2		-		1.0		-
Ending accumulated derivative gain / (loss) in AOCI	$	(7.6)	$	18.6	$	-	$	19.2

	Nine months ended				Nine months ended
	September 30, 2014				September 30, 2013
			Interest				Interest
$ in millions (net of tax)	Power		Rate Hedge		Power		Rate Hedge
Beginning accumulated derivative gain / (loss) in AOCI	$	1.4	$	19.2	$	(3.0)	$	0.5
Net gains / (losses) associated with current period hedging transactions		(23.8)		-		-		18.7
Net gains / (losses) reclassified to earnings
Interest expense		-		(0.6)		-		-
Revenues		15.4		-		1.3		-
Purchased power		(0.6)		-		1.7		-
Ending accumulated derivative gain / (loss) in AOCI	$	(7.6)	$	18.6	$	-	$	19.2
Portion expected to be reclassified to earnings in the next twelve months (a)	$	(7.3)	$	(0.6)
Maximum length of time that we are hedging our exposure to variability in future cash flows related to forecasted transactions (in months)		27		0

Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location

For the three months ended September 30, 2014
$ in millions	Heating Oil		FTRs		Power		Total
Change in unrealized gain / (loss)	$	(0.2)	$	0.3	$	(2.3)	$	(2.2)
Realized gain / (loss)		-		0.1		(2.1)		(2.0)
Total	$	(0.2)	$	0.4	$	(4.4)	$	(4.2)
Recorded on Balance Sheet:
Regulatory asset	$	(0.1)	$	-	$	-	$	(0.1)
Recorded in Income Statement: gain / (loss)
Purchased power		-		0.4		(4.4)		(4.0)
Fuel		(0.1)		-		-		(0.1)
Total	$	(0.2)	$	0.4	$	(4.4)	$	(4.2)

For the three months ended September 30, 2013
$ in millions	Heating Oil		FTRs		Power		Total
Change in unrealized gain	$	0.1	$	1.3	$	0.1	$	1.5
Realized gain / (loss)		0.1		-		(0.8)		(0.7)
Total	$	0.2	$	1.3	$	(0.7)	$	0.8
Recorded in Income Statement: gain / (loss)
Purchased power	$	-	$	1.3	$	(0.7)	$	0.6
Fuel		0.1		-		-		0.1
O&M		0.1		-		-		0.1
Total	$	0.2	$	1.3	$	(0.7)	$	0.8

For the nine months ended September 30, 2014
$ in millions	Heating Oil		FTRs		Power		Total
Change in unrealized loss	$	(0.3)	$	(1.2)	$	(6.0)	$	(7.5)
Realized gain / (loss)		0.1		0.7		(3.6)		(2.8)
Total	$	(0.2)	$	(0.5)	$	(9.6)	$	(10.3)
Recorded on Balance Sheet:
Regulatory asset	$	(0.1)	$	-	$	-	$	(0.1)
Recorded in Income Statement: loss
Purchased power		-		(0.5)		(9.6)		(10.1)
Fuel		(0.1)		-		-		(0.1)
Total	$	(0.2)	$	(0.5)	$	(9.6)	$	(10.3)

For the nine months ended September 30, 2013
$ in millions	Heating Oil		FTRs		Power		Total
Change in unrealized gain / (loss)	$	(0.2)	$	0.4	$	10.5	$	10.7
Realized gain		-		1.2		0.5		1.7
Total	$	(0.2)	$	1.6	$	11.0	$	12.4
Recorded on Balance Sheet:
Regulatory asset	$	(0.1)	$	-	$	-	$	(0.1)
Recorded in Income Statement: gain / (loss)
Purchased power		-		1.6		11.0		12.6
Fuel		(0.1)		-		-		(0.1)
Total	$	(0.2)	$	1.6	$	11.0	$	12.4

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]

Fair Values of Derivative Instruments
at September 30, 2014
				Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets
$ in millions	Hedging Designation	Gross Fair Value as presented in the Condensed Consolidated Balance Sheets		Financial Instruments with Same Counterparty in Offsetting Position		Cash Collateral		Net Amount
Assets
Short-term derivative positions (presented in Other current assets)
Forward power contracts	Cash Flow	$	0.9	$	(0.9)	$	-	$	-
Forward power contracts	MTM		6.3		(5.4)		-		0.9
Heating oil	MTM		-		-		-		-
Long-term derivative positions (presented in Other deferred assets)
Forward power contracts	Cash Flow		0.7		(0.6)		(0.1)		-
Forward power contracts	MTM		3.3		(2.5)		-		0.8
Total assets		$	11.2	$	(9.4)	$	(0.1)	$	1.7
Liabilities
Short-term derivative positions (presented in Other current liabilities)
Forward power contracts	Cash Flow	$	12.0	$	(0.9)	$	(9.8)	$	1.3
Forward power contracts	MTM		10.2		(5.4)		(2.8)		2.0
Heating oil	MTM		0.1		-		(0.1)		-
FTRs	MTM		1.0		-		-		1.0
Long-term derivative positions (presented in Other deferred liabilities)
Forward power contracts	Cash Flow		1.3		(0.6)		(0.7)		-
Forward power contracts	MTM		3.4		(2.6)		(0.7)		0.1
Total liabilities		$	28.0	$	(9.5)	$	(14.1)	$	4.4

Fair Values of Derivative Instruments
at December 31, 2013
				Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets
$ in millions	Hedging Designation	Gross Fair Value as presented in the Condensed Consolidated Balance Sheets		Financial Instruments with Same Counterparty in Offsetting Position		Cash Collateral		Net Amount
Assets
Short-term derivative positions (presented in Other current assets)
Forward power contracts	Cash Flow	$	0.5	$	(0.2)	$	-	$	0.3
Forward power contracts	MTM		4.9		(4.2)		-		0.7
FTRs	MTM		0.2		-		-		0.2
Heating oil futures	MTM		0.2		-		(0.2)		-
Long-term derivative positions (presented in Other deferred assets)
Forward power contracts	Cash Flow		3.0		-		(3.0)		-
Forward power contracts	MTM		5.0		(0.3)		-		4.7
Total assets		$	13.8	$	(4.7)	$	(3.2)	$	5.9
Liabilities
Short-term derivative positions (presented in Other current liabilities)
Forward power contracts	Cash Flow	$	2.7	$	(0.2)	$	(2.3)	$	0.2
Forward power contracts	MTM		6.6		(4.2)		(2.3)		0.1
Long-term derivative positions (presented in Other deferred liabilities)
Forward power contracts	MTM		1.3		(0.3)		(1.0)		-
Total liabilities		$	10.6	$	(4.7)	$	(5.6)	$	0.3

DP&L [Member]

Schedule of Notional Amounts of Outstanding Derivative Positions

Commodity	Accounting Treatment		Unit	Purchases (in thousands)		Sales (in thousands)		Net Purchases/ (Sales) (in thousands)
FTRs		Mark to Market	MWh		17.4		-		17.4
Heating oil futures		Mark to Market	Gallons		672.0		-		672.0
Forward power contracts		Cash Flow Hedge	MWh		40.7		(3,543.0)		(3,502.3)
Forward power contracts		Mark to Market	MWh		2,320.0		(3,463.5)		(1,143.5)

Commodity	Accounting Treatment		Unit	Purchases (in thousands)		Sales (in thousands)		Net Purchases/ (Sales) (in thousands)
FTRs		Mark to Market	MWh		7.1		-		7.1
Heating oil futures		Mark to Market	Gallons		1,428.0		-		1,428.0
Forward power contracts		Cash Flow Hedge	MWh		140.4		(4,705.7)		(4,565.3)
Forward power contracts		Mark to Market	MWh		3,172.4		(2,888.5)		283.9

Gains or Losses Recognized in AOCI for the Cash Flow Hedges

	Three months ended				Three months ended
	September 30, 2014				September 30, 2013
			Interest				Interest
$ in millions (net of tax)	Power		Rate Hedge		Power		Rate Hedge
Beginning accumulated derivative gain / (loss) in AOCI	$	(14.0)	$	4.6	$	(1.9)	$	6.1
Net gains / (losses) associated with current period hedging transactions		1.4		-		(0.3)		-
Net gains / (losses) reclassified to earnings
Interest expense		-		(0.2)		-		(0.6)
Revenues		3.2		-		0.3		-
Purchased power		0.2		-		1.3		-
Ending accumulated derivative gain / (loss) in AOCI	$	(9.2)	$	4.4	$	(0.6)	$	5.5

	Nine months ended				Nine months ended
	September 30, 2014				September 30, 2013
			Interest				Interest
$ in millions (net of tax)	Power		Rate Hedge		Power		Rate Hedge
Beginning accumulated derivative gain / (loss) in AOCI	$	1.0	$	5.2	$	(4.7)	$	7.3
Net losses associated with current period hedging transactions		(26.3)		-		-		-
Net gains / (losses) reclassified to earnings
Interest expense		-		(0.8)		-		(1.8)
Revenues		16.6		-		1.4		-
Purchased power		(0.5)		-		2.7		-
Ending accumulated derivative gain / (loss) in AOCI	$	(9.2)	$	4.4	$	(0.6)	$	5.5
Portion expected to be reclassified to earnings in the next twelve months (a)	$	(7.2)	$	(1.1)
Maximum length of time that we are hedging our exposure to variability in future cash flows related to forecasted transactions (in months)		27		0

Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location

For the three months ended September 30, 2014
$ in millions	Heating Oil		FTRs		Power		Total
Change in unrealized gain / (loss)	$	(0.2)	$	0.3	$	(2.7)	$	(2.6)
Realized gain / (loss)		-		0.1		(2.1)		(2.0)
Total	$	(0.2)	$	0.4	$	(4.8)	$	(4.6)
Recorded on Balance Sheet:
Regulatory asset	$	(0.1)	$	-	$	-	$	(0.1)
Recorded in Income Statement: gain / (loss)
Revenues		-		-		(0.3)		(0.3)
Purchased power		-		0.4		(4.5)		(4.1)
Fuel		(0.1)		-		-		(0.1)
Total	$	(0.2)	$	0.4	$	(4.8)	$	(4.6)

For the three months ended September 30, 2013
$ in millions	Heating Oil		FTRs		Power		Total
Change in unrealized gain / (loss)	$	0.1	$	1.3	$	(0.1)	$	1.3
Realized gain / (loss)		0.1		-		(0.8)		(0.7)
Total	$	0.2	$	1.3	$	(0.9)	$	0.6
Recorded in Income Statement: gain / (loss)
Revenues	$	-	$	-	$	0.1	$	0.1
Purchased power		-		1.3		(1.0)		0.3
Fuel		0.1		-		-		0.1
O&M		0.1		-		-		0.1
Total	$	0.2	$	1.3	$	(0.9)	$	0.6

For the nine months ended September 30, 2014
$ in millions	Heating Oil		FTRs		Power		Total
Change in unrealized loss	$	(0.3)	$	(1.2)	$	(5.7)	$	(7.2)
Realized gain / (loss)		0.1		0.7		(3.0)		(2.2)
Total	$	(0.2)	$	(0.5)	$	(8.7)	$	(9.4)
Recorded on Balance Sheet:
Regulatory asset	$	(0.1)	$	-	$	-	$	(0.1)
Recorded in Income Statement: gain / (loss)
Revenues		-		-		1.0		1.0
Purchased power		-		(0.5)		(9.7)		(10.2)
Fuel		(0.1)		-		-		(0.1)
Total	$	(0.2)	$	(0.5)	$	(8.7)	$	(9.4)

For the nine months ended September 30, 2013
$ in millions	Heating Oil		FTRs		Power		Total
Change in unrealized gain / (loss)	$	(0.2)	$	0.4	$	8.9	$	9.1
Realized gain		-		1.2		1.1		2.3
Total	$	(0.2)	$	1.6	$	10.0	$	11.4
Recorded on Balance Sheet:
Regulatory asset	$	(0.1)	$	-	$	-	$	(0.1)
Recorded in Income Statement: gain / (loss)
Revenues		-		-		0.2		0.2
Purchased power		-		1.6		9.8		11.4
Fuel		(0.1)		-		-		(0.1)
Total	$	(0.2)	$	1.6	$	10.0	$	11.4

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]

Fair Values of Derivative Instruments
at September 30, 2014
				Gross Amounts Not Offset in the Condensed Balance Sheets
$ in millions	Hedging Designation	Gross Fair Value as presented in the Condensed Balance Sheets		Financial Instruments with Same Counterparty in Offsetting Position		Cash Collateral		Net Amount
Assets
Short-term derivative positions (presented in Other current assets)
Forward power contracts	Cash Flow	$	0.9	$	(0.9)	$	-	$	-
Forward power contracts	MTM		6.5		(5.4)		-		1.1
Heating oil futures	MTM		-		-		-		-
Long-term derivative positions (presented in Other deferred assets)
Forward power contracts	Cash Flow		0.7		(0.6)		(0.1)		-
Forward power contracts	MTM		3.6		(2.6)		-		1.0
Total assets		$	11.7	$	(9.5)	$	(0.1)	$	2.1
Liabilities
Short-term derivative positions (presented in Other current liabilities)
Forward power contracts	Cash Flow	$	12.0	$	(0.9)	$	(9.8)	$	1.3
Forward power contracts	MTM		10.2		(5.4)		(2.8)		2.0
Heating oil futures	MTM		0.1		-		(0.1)		-
FTRs	MTM		1.0		-		-		1.0
Long-term derivative positions (presented in Other deferred liabilities)
Forward power contracts	Cash Flow		1.3		(0.6)		(0.7)		-
Forward power contracts	MTM		3.4		(2.6)		(0.7)		0.1
Total liabilities		$	28.0	$	(9.5)	$	(14.1)	$	4.4

Fair Values of Derivative Instruments
at December 31, 2013
				Gross Amounts Not Offset in the Condensed Balance Sheets
$ in millions	Hedging Designation	Gross Fair Value as presented in the Condensed Balance Sheets		Financial Instruments with Same Counterparty in Offsetting Position		Cash Collateral		Net Amount
Assets
Short-term derivative positions (presented in Other current assets)
Forward power contracts	Cash Flow	$	0.5	$	(0.2)	$	-	$	0.3
Forward power contracts	MTM		4.9		(4.2)		-		0.7
FTRs	MTM		0.2						0.2
Heating oil futures	MTM		0.2		-		(0.2)		-
Long-term derivative positions (presented in Other deferred assets)
Forward power contracts	Cash Flow		3.0		-		(3.0)		-
Forward power contracts	MTM		5.0		(0.3)		-		4.7
Total assets		$	13.8	$	(4.7)	$	(3.2)	$	5.9
Liabilities
Short-term derivative positions (presented in Other current liabilities)
Forward power contracts	Cash Flow	$	2.7	$	(0.2)	$	(2.3)	$	0.2
Forward power contracts	MTM		6.6		(4.2)		(2.3)		0.1
Long-term derivative positions (presented in Other deferred liabilities)
Forward power contracts	MTM		1.3		(0.3)		(1.0)		-
Total liabilities		$	10.6	$	(4.7)	$	(5.6)	$	0.3