Quarterly report pursuant to Section 13 or 15(d)

Organization and Basis of Presentation (Details)

v3.21.1
Organization and Basis of Presentation (Details)
a in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2021
a
segment
Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Line Items]    
Number of operating segments | segment 2  
1/16th nonparticipating perpetual royalty interest    
Organization, Consolidation and Presentation of Financial Statements [Line Items]    
Nonparticipating perpetual royalty interest rate 6.25% 6.25%
1/128th nonparticipating perpetual royalty interest    
Organization, Consolidation and Presentation of Financial Statements [Line Items]    
Nonparticipating perpetual royalty interest rate 0.78125% 0.78125%
1/8th Net Royalty Acres    
Organization, Consolidation and Presentation of Financial Statements [Line Items]    
Nonparticipating perpetual royalty interest rate 12.50%  
West Texas    
Organization, Consolidation and Presentation of Financial Statements [Line Items]    
Area of land (in acres) 880  
West Texas | 1/128th Nonparticipating Perpetual Oil and Gas Royalty Interest    
Organization, Consolidation and Presentation of Financial Statements [Line Items]    
Area of land (in acres) 85  
West Texas | 1/16th Nonparticipating Perpetual Oil and Gas Royalty Interest    
Organization, Consolidation and Presentation of Financial Statements [Line Items]    
Area of land (in acres) 371  
West Texas | 1/8th Net Royalty Acres    
Organization, Consolidation and Presentation of Financial Statements [Line Items]    
Area of land (in acres) 4