Note 13 - Junior Subordinated Debentures (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Note 13 - Junior Subordinated Debentures (Details) [Line Items]
Number Of Wholly Owned Trusts	1boch_NumberOfWhollyOwnedTrusts	2boch_NumberOfWhollyOwnedTrusts
Repayments of Subordinated Debt (in Dollars)	$ 4,629,000us-gaap_RepaymentsOfSubordinatedDebt
Gains (Losses) on Extinguishment of Debt (in Dollars)	406,000
Reduction in Common Stock Held in Trust (in Dollars)	155,000boch_ReductionInCommonStockHeldInTrust
Subordinated Debt (in Dollars)	10,310,000us-gaap_SubordinatedDebt	15,465,000us-gaap_SubordinatedDebt
Trust Preferred Securities Restricted Core Capital Percent	10.00%	15.00%
Bank of Commerce Holdings Trust [Member] \| Junior Subordinated Debt [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Note 13 - Junior Subordinated Debentures (Details) [Line Items]
Debt Instrument, Basis Spread on Variable Rate		3.30%
Bank of Commerce Holdings Trust [Member] \| Junior Subordinated Debt [Member]
Note 13 - Junior Subordinated Debentures (Details) [Line Items]
Debt Instrument, Increase (Decrease), Net (in Dollars)	(5,200,000)
Repayments of Subordinated Debt (in Dollars)	4,600,000
Gains (Losses) on Extinguishment of Debt (in Dollars)	406,000
Debt Instrument Annual Increase Cap Rate		2.75%
Debt Instrument Lifetime Cap Rate		12.50%
Subordinated Debt (in Dollars)		5,155,000
Bank of Commerce Holdings Trust [Member]
Note 13 - Junior Subordinated Debentures (Details) [Line Items]
Common Stock Held in Trust (in Dollars)		465,000
Bank of Commerce Holdings Trust II [Member] \| Junior Subordinated Debt [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Note 13 - Junior Subordinated Debentures (Details) [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.58%	1.58%
Bank of Commerce Holdings Trust II [Member] \| Junior Subordinated Debt [Member]
Note 13 - Junior Subordinated Debentures (Details) [Line Items]
Subordinated Debt (in Dollars)	10,310,000	10,310,000
Bank of Commerce Holdings Trust II [Member]
Note 13 - Junior Subordinated Debentures (Details) [Line Items]
Common Stock Held in Trust (in Dollars)	310,000
Junior Subordinated Debt [Member]
Note 13 - Junior Subordinated Debentures (Details) [Line Items]
Number Of Wholly Owned Trusts	1	2
Subordinated Debt (in Dollars)		$ 15,500,000

Debt instrument annual increase cap rate.

No definition available.

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- Definition

Debt instrument lifetime cap rate.

+ References

No definition available.

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- Definition

Number of wholly-owned trusts.

+ References

No definition available.

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- Definition

Reduction in the value of common stock held in trust.

+ References

No definition available.

+ Details

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- Definition

Trust preferred securities restricted core capital percent.

+ References

No definition available.

+ Details

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- Definition

Value of common stock held in trust.

+ References

No definition available.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

Net increase or decrease in the carrying amount of the debt instrument for the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(f))

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph f

-Article 4

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- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

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- Definition

The cash outflow from the repayment of long-term borrowing where a lender is placed in a lien position behind debt having a higher priority of repayment (senior) in case of liquidation of the entity's assets or underlying collateral.

+ References

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-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

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-Paragraph 1

-Subparagraph (SX 210.9-03.16)

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 10

-Section F

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Article 5

-Subsection 19, 20, 22

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