| Cover | 3 Months Ended | 9 Months Ended |
| Dec. 31, 2021 | Sep. 30, 2021 | |
| Document Information [Line Items] | ||
| Document Type | 8-K | |
| Document Period End Date | Nov. 15, 2021 | |
| Entity Registrant Name | LCNB CORP. | |
| Entity Tax Identification Number | 31-1626393 | |
| Entity Incorporation, State or Country Code | OH | |
| Entity File Number | 001-35292 | |
| Entity Address, Address Line One | 2 North Broadway | |
| Entity Address, State or Province | OH | |
| Entity Address, City or Town | Lebanon | |
| Entity Address, Postal Zip Code | 45036 | |
| City Area Code | (513) | |
| Local Phone Number | 932-1414 | |
| Written Communications | false | |
| Soliciting Material | false | |
| Pre-commencement Tender Offer | false | |
| Pre-commencement Issuer Tender Offer | false | |
| Title of 12(b) Security | Common Stock, No Par Value | |
| Trading Symbol | LCNB | |
| Security Exchange Name | NASDAQ | |
| Entity Emerging Growth Company | false | |
| Amendment Flag | false | |
| Entity Central Index Key | 0001074902 |
