| Cover | Sep. 07, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 7, 2021 |
| Entity File Number | 001-35272 |
| Entity Registrant Name | Midland States Bancorp, Inc. |
| Entity Central Index Key | 0001466026 |
| Entity Tax Identification Number | 37-1233196 |
| Entity Incorporation, State or Country Code | IL |
| Entity Address, Address Line One | 1201 Network Centre Drive |
| Entity Address, City or Town | Effingham |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 62401 |
| City Area Code | 217 |
| Local Phone Number | 342-7321 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common stock, $0.01 par value |
| Trading Symbol | MSBI |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
