| Document and Entity Information | Oct. 16, 2020 |
| Entity Listings [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Oct. 16, 2020 |
| Entity Registrant Name | Jernigan Capital, Inc. |
| Entity Incorporation, State or Country Code | MD |
| Entity File Number | 001-36892 |
| Entity Tax Identification Number | 47-1978772 |
| Entity Address, Address Line One | 6410 Poplar Avenue |
| Entity Address, Address Line Two | Suite 650 |
| Entity Address, City or Town | Memphis |
| Entity Address, State or Province | TN |
| Entity Address, Postal Zip Code | 38119 |
| City Area Code | 901 |
| Local Phone Number | 567-9510 |
| Written Communications | false |
| Soliciting Material | true |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | true |
| Entity Central Index Key | 0001622353 |
| Common Stock [Member] | |
| Entity Listings [Line Items] | |
| Title of 12(b) Security | Common stock, par value $0.01 per share |
| Trading Symbol | JCAP |
| Security Exchange Name | NYSE |
| 7.00% Series B cumulative redeemable perpetual preferred stock, $0.01 par value per share [Member] | |
| Entity Listings [Line Items] | |
| Title of 12(b) Security | 7.00% Series B cumulative redeemable perpetual preferred stock, $0.01 par value per share |
| Trading Symbol | JCAP PR B |
| Security Exchange Name | NYSE |
