| Document and Entity Information | May 14, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | EQUITY BANCSHARES INC |
| Security Exchange Name | NASDAQ |
| Amendment Flag | false |
| Entity Central Index Key | 0001227500 |
| Document Type | 8-K |
| Document Period End Date | May 14, 2021 |
| Entity Incorporation State Country Code | KS |
| Entity File Number | 001-37624 |
| Entity Tax Identification Number | 72-1532188 |
| Entity Address, Address Line One | 7701 East Kellogg Drive |
| Entity Address, Address Line Two | Suite 300 |
| Entity Address, City or Town | Wichita |
| Entity Address, State or Province | KS |
| Entity Address, Postal Zip Code | 67207 |
| City Area Code | 316 |
| Local Phone Number | 612.6000 |
| Written Communications | true |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Class A, Common Stock, par value $0.01 per share |
| Trading Symbol | EQBK |
| Entity Emerging Growth Company | false |
