v3.5.0.2
Document and Entity Information - shares
9 Months Ended
Sep. 30, 2016
Nov. 03, 2016
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2016  
Document Fiscal Year Focus 2016  
Document Fiscal Period Focus Q3  
Trading Symbol BSM  
Entity Registrant Name Black Stone Minerals, L.P.  
Entity Central Index Key 0001621434  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Common Units    
Document Information [Line Items]    
Entity Partnership Units Outstanding   95,736,113
Subordinated Units    
Document Information [Line Items]    
Entity Partnership Units Outstanding   95,189,076
Preferred Units    
Document Information [Line Items]    
Entity Partnership Units Outstanding   52,691