| Document And Entity Information | Apr. 27, 2023 |
| Document Information [Line Items] | |
| Entity, Registrant Name | CONNECTONE BANCORP, INC. |
| Document, Type | 8-K |
| Document, Period End Date | Apr. 27, 2023 |
| Entity, Incorporation, State or Country Code | NJ |
| Entity, File Number | 001-40751 |
| Entity, Tax Identification Number | 52-1273725 |
| Entity, Address, Address Line One | 301 Sylvan Avenue |
| Entity, Address, City or Town | Englewood Cliffs |
| Entity, Address, State or Province | NJ |
| Entity, Address, Postal Zip Code | 07632 |
| City Area Code | 201 |
| Local Phone Number | 816-8900 |
| 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 | 0000712771 |
| CommonStock Custom [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Common stock |
| Trading Symbol | CNOB |
| Security Exchange Name | NASDAQ |
| DepositarySharesEachRepresentingA140thInterestInAShareOf525SeriesANoncumulativePerpetualPreferredStock Custom [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Depositary Shares (each representing a 1/40th interest in a share of 5.25% Series A Non-Cumulative, perpetual preferred stock) |
| Trading Symbol | CNOBP |
| Security Exchange Name | NASDAQ |
