v3.7.0.1
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2017
Aug. 02, 2017
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q2  
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 Large Accelerated Filer  
Common Units    
Document Information [Line Items]    
Entity Partnership Units Outstanding (in shares)   100,660,009
Subordinated Units    
Document Information [Line Items]    
Entity Partnership Units Outstanding (in shares)   95,388,424
Preferred Units    
Document Information [Line Items]    
Entity Partnership Units Outstanding (in shares)   26,426