Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2011
Entity Registrant Name	DPL INC
Entity Central Index Key	0000787250
Document Type	10-K
Document Period End Date	Dec. 31, 2011
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding	1
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q4
Entity Voluntary Filers	Yes
Entity Well-known Seasoned Issuer	No
Entity Public Float	$ 0