Note 14 - Junior Subordinated Debentures (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Number Of Wholly Owned Trusts	1	1
Junior Subordinated Notes	$ 10,310	$ 10,310
Repayments of Subordinated Debt			$ 4,629
Gain (Loss) on Extinguishment of Debt			406
Reduction in Common Stock Held in Trust			155
Bank of Commerce Holdings Trust II [Member]
Common Stock Held in Trust	$ 310	$ 310
Junior Subordinated Debt [Member] | Bank of Commerce Holdings Trust II [Member]
Debt Instrument, Interest Rate, Effective Percentage	2.54%	1.92%
Debt Instrument, Basis Spread on Variable Rate	1.58%
Junior Subordinated Notes	$ 10,310
Debt Instrument, Increase (Decrease), Net			(5,200)
Repayments of Subordinated Debt			4,600
Gain (Loss) on Extinguishment of Debt			$ 406