Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Aug. 06, 2019
Document And Entity Information
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Entity File Number	000-11486
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Registrant Name	CONNECTONE BANCORP, INC.
Entity Incorporation, State or Country Code	NJ
Entity Address, City or Town	Englewood Cliffs
Entity Address, State or Province	NJ
Entity Tax Identification Number	52-1273725
Entity Address, Address Line One	301 Sylvan Avenue
Entity Address, Postal Zip Code	07632
Local Phone Number	201-816-8900
Entity Information, Former Legal or Registered Name	N/A
Entity Common Stock, Shares Outstanding		35,352,866
Entity Central Index Key	0000712771
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Small Business	false
City Area Code	201
Document Quarterly Report	true
Document Transition Report	false
Entity Shell Company	false
Title of 12(b) Security	Common stock
Trading Symbol	CNOB
Name of Exchange on which Security is Registered	NASDAQ