Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Aug. 06, 2021
Document And Entity Information
Document Type	10-Q
Entity Central Index Key	0000712771
Document Period End Date	Jun. 30, 2021
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	000-11486
Entity Registrant Name	CONNECTONE BANCORP, INC.
Entity Incorporation, State or Country Code	NJ
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
Title of 12(b) Security	Common stock
Trading Symbol	CNOB
Name of Exchange on which Security is Registered	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Information, Former Legal or Registered Name	N/A
Entity Common Stock, Shares Outstanding		39,794,815