Document And Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2015
Feb. 10, 2016
Jun. 30, 2015
Document Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2015    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Entity Registrant Name COLUMBIA PIPELINE PARTNERS LP/DE    
Entity Central Index Key 0001420783    
Current Fiscal Year End Date --12-31    
Entity Filer Category Non-accelerated Filer    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 1,353,717,666
Common Units      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   53,834,784  
Subordinated Units      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   46,811,398