v3.19.3
Cover - shares
9 Months Ended
Sep. 30, 2019
Oct. 30, 2019
Entity Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2019  
Document Transition Report false  
Entity File Number 001-37362  
Entity Registrant Name Black Stone Minerals, L.P.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 47-1846692  
Entity Address, Address Line One 1001 Fannin Street, Suite 2020  
Entity Address, City or Town Houston,  
Entity Address, State or Province TX  
Entity Address, Postal Zip Code 77002  
City Area Code (713)  
Local Phone Number 445-3200  
Title of 12(b) Security Common Units Representing Limited Partner Interests  
Trading Symbol BSM  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Smaller reporting company false  
Emerging growth company false  
Entity shell company false  
Amendment Flag false  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Entity Central Index Key 0001621434  
Current Fiscal Year End Date --12-31  
Common Units    
Entity Information [Line Items]    
Entity Partnership Units Outstanding (in shares)   205,959,790
Preferred Units    
Entity Information [Line Items]    
Entity Partnership Units Outstanding (in shares)   14,711,219