| Document And Entity Information | Apr. 01, 2022 |
| Document Information [Line Items] | |
| Entity, Registrant Name | BOSTON OMAHA CORPORATION |
| Document, Type | 8-K |
| Document, Period End Date | Apr. 1, 2022 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, File Number | 001-38113 |
| 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 |
| Trading Symbol | BOC |
| Security Exchange Name | NYSE |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001494582 |
