XML 72 R57.htm IDEA: XBRL DOCUMENT v3.7.0.1
Contractual Obligations, Commercial Commitments and Contingencies (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2017
Dec. 31, 2016
Public Utility, Property, Plant and Equipment [Line Items]    
Due to third parties, current $ 2.4 $ 2.3
THE DAYTON POWER AND LIGHT COMPANY [Member]    
Public Utility, Property, Plant and Equipment [Line Items]    
Debt maturity, earliest 2018  
Debt maturity, latest 2040  
DPLE [Member]    
Public Utility, Property, Plant and Equipment [Line Items]    
Third party guarantees $ 24.6  
Debt Obligation on 4.9% Equity Ownership [Member] | THE DAYTON POWER AND LIGHT COMPANY [Member]    
Public Utility, Property, Plant and Equipment [Line Items]    
Equity ownership interest 4.90%  
Equity ownership interest aggregate cost $ 72.5  
Electric Generation Company [Member] | THE DAYTON POWER AND LIGHT COMPANY [Member]    
Public Utility, Property, Plant and Equipment [Line Items]    
Debt obligation $ 1,479.6