Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Nov. 09, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	ConnectOne Bancorp, Inc.
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		30,084,744
Amendment Flag	true
Amendment Description	Correct certain data in the notes to financial statements.
Entity Central Index Key	0000712771
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2