XML 14 R1.htm IDEA: XBRL DOCUMENT v3.21.1
Document And Entity Information - shares
 3 Months Ended
Mar. 31, 2021
May 24, 2021
Document Information [Line Items]    
Entity Central Index Key 0001494582  
Entity Registrant Name BOSTON OMAHA Corp  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Document Fiscal Period Focus Q1  
Document Fiscal Year Focus 2021  
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2021  
Document Transition Report false  
Entity File Number 001-38113  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 27-0788438  
Entity Address, Address Line One 1601 Dodge Street, Suite 3300  
Entity Address, City or Town Omaha  
Entity Address, State or Province NE  
Entity Address, Postal Zip Code 68102  
City Area Code 857  
Local Phone Number 256-0079  
Title of 12(b) Security Class A common stock, $0.001 par value per share  
Trading Symbol BOMN  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Common Class B [Member]    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   1,055,560
Common Class A [Member]    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   28,520,555