Reserve for Disallaowance of Regulatory Asset

No definition available.

Name:	dpl_Reservefordisallowanceofregulatoryasset
Namespace Prefix:	dpl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Discloses the amount of any reduction to the carrying amounts of regulated assets that result from impairment (for example, rate actions of a regulator).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 340

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6066304&loc=d3e44026-110379

+ Details

Name:	us-gaap_AmountOfImpairmentToCarryingAmountOfRegulatoryAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 340

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

+ Details

Name:	us-gaap_RegulatoryAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 405

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394

+ Details

Name:	us-gaap_RegulatoryLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

A noncash adjustment to the provision established for storm damage by an oil, gas, or utility company.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

+ Details

Name:	us-gaap_StormDamageProvision
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_RegulatoryAssetAxis=dpl_FuelDeferralMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAssetAxis=us-gaap_StormCostsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Regulatory Matters (Narrative) (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended	6 Months Ended
	Apr. 14, 2014	Dec. 31, 2014	Jun. 30, 2013	Dec. 31, 2013	Sep. 30, 2013
Regulatory Assets		$ 211.7us-gaap_RegulatoryAssets		$ 180.5us-gaap_RegulatoryAssets
Regulatory Liabilities		128.5us-gaap_RegulatoryLiabilities		121.1us-gaap_RegulatoryLiabilities
Storm Damage Provision	22.3us-gaap_StormDamageProvision
Deferred Storm Costs [Member]
Storm Damage Provision		22.3
Fuel and purchased power recovery costs
Disallowance of regulatory asset			5.3		2.6
ReserveForDisallowanceofRegulatoryAsset			$ 2.6