Acquisition (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Jul. 01, 2014
Acquisition (Details) [Line Items]
Common Stock Conversion Ratio Shares (in Shares)	2.6
Goodwill Recorded in Business Acquisition	$ 129,105,000	$ 129,105,000
Finite Lived Intangible Asset Acquired		5,308,000
Business Combination, Consideration Transferred	264,231
Finite-Lived Intangible Asset, Useful Life	10 years
Business Combination, Acquisition Related Costs	10,600,000
Business Combination Expenses Excluded from Non Interest Expenses	13,500,000
Business Combination Income Tax Benefits Related To Merger Expenses	3,900,000
Legacy ConnectOne [Member]
Acquisition (Details) [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets		1,500,000,000
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Non Current Loans		1,200,000,000
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Non Current Deposits		$ 1,100,000,000