Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
NUMERATORS:
Net income attributable to Bank of Commerce Holdings	$ 2,252	$ 1,486	$ 4,312	$ 3,150
Less:
Preferred stock dividends	248	212	434	425
Accretion on preferred stock	0	23	0	45	0
Income available to common shareholders	$ 2,004	$ 1,251	$ 3,878	$ 2,680
DENOMINATORS:
Weighted average number of common shares outstanding - basic	16,302,000	16,991,000	16,553,000	16,991,000
Effect of potentially dilutive common shares	0	0	0	0
Weighted average number of common shares outstanding - diluted	16,302,000	16,991,000	16,553,000	16,991,000
EARNINGS PER COMMON SHARE:
Basic	$ 0.12	$ 0.07	$ 0.23	$ 0.16
Diluted	$ 0.12	$ 0.07	$ 0.23	$ 0.16
Stock Options [Member]
EARNINGS PER COMMON SHARE:
Anti-dilutive options and warrants not included in earnings per share calculation	410,455	256,580	410,455	256,580
Warrant [Member]
EARNINGS PER COMMON SHARE:
Anti-dilutive options and warrants not included in earnings per share calculation	0	435,410	0	435,410