v3.10.0.1
Document and Entity Information - shares
9 Months Ended
Sep. 30, 2018
Nov. 06, 2018
Entity Registrant Name Falcon Minerals Corp  
Entity Central Index Key 0001703785  
Amendment Flag false  
Trading Symbol FLMN  
Current Fiscal Year End Date --12-31  
Document Type 10-Q  
Document Period End Date Sep. 30, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q3  
Entity Filer Category Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Class A common stock    
Entity Common Stock, Shares Outstanding   45,855,000
Class C common stock    
Entity Common Stock, Shares Outstanding   40,000,000