Note 5 - Loans (Details) - Allowance for Credit Losses and Recorded Investment in Financing Receivables (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
ALLL:
Beginning balance	$ 14,172	$ 11,103
Ending balance	10,820	14,172
Allowance for credit losses: individually evaluated for impairment	1,556	4,994
Allowance for credit losses: collectively evaluated for impairment	9,264	9,178
Charge offs	(7,319)	(2,770)
Recoveries	792	3,089
Provision	3,175	2,750
Financing receivables
Financing receivables	660,898boch_FinancingReceivableEndingBalance	597,995boch_FinancingReceivableEndingBalance
Financing receivables: individually evaluated for impairment	31,408	42,141
Financing receivables: collectively evaluated for impairment	629,490	555,854
Commercial Portfolio Segment [Member]
ALLL:
Beginning balance	7,057	4,168
Ending balance	3,552	7,057
Allowance for credit losses: individually evaluated for impairment	314	2,988
Allowance for credit losses: collectively evaluated for impairment	3,238	4,069
Charge offs	(4,242)	(882)
Recoveries	582	58
Provision	155	3,713
Financing receivables
Financing receivables	153,957	170,429
Financing receivables: individually evaluated for impairment	6,597	6,590
Financing receivables: collectively evaluated for impairment	147,360	163,839
Commercial Real Estate Portfolio Segment [Member]
ALLL:
Beginning balance	2,784	2,783
Ending balance	4,825	2,784
Allowance for credit losses: individually evaluated for impairment	432	814
Allowance for credit losses: collectively evaluated for impairment	4,393	1,970
Charge offs	(2,699)	(230)
Recoveries	1	2,483
Provision	4,739	(2,252)
Financing receivables
Financing receivables	360,602	307,905
Financing receivables: individually evaluated for impairment	11,753	21,747
Financing receivables: collectively evaluated for impairment	348,849	286,158
Consumer Portfolio Segment [Member]
ALLL:
Beginning balance	35	28
Ending balance	450	35
Allowance for credit losses: individually evaluated for impairment	15
Allowance for credit losses: collectively evaluated for impairment	435	35
Charge offs	(2)	(25)
Recoveries		1
Provision	417	31
Financing receivables
Financing receivables	35,372	3,508
Financing receivables: individually evaluated for impairment	35
Financing receivables: collectively evaluated for impairment	35,337	3,508
Residential Portfolio Segment [Member]
ALLL:
Beginning balance	2,493	3,335
Ending balance	1,671	2,493
Allowance for credit losses: individually evaluated for impairment	795	1,192
Allowance for credit losses: collectively evaluated for impairment	876	1,301
Charge offs	(376)	(1,633)
Recoveries	209	547
Provision	(655)	244
Financing receivables
Financing receivables	110,967	116,153
Financing receivables: individually evaluated for impairment	13,023	13,804
Financing receivables: collectively evaluated for impairment	97,944	102,349
Unallocated Financing Receivables [Member]
ALLL:
Beginning balance	1,803	789
Ending balance	322	1,803
Allowance for credit losses: collectively evaluated for impairment	322	1,803
Provision	$ (1,481)	$ 1,014

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Financing receivable allowance for credit losses, provision.

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Financing receivable ending balance.

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A valuation allowance for financing receivables that are expected to be uncollectible.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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

-Publisher FASB

-Name Accounting Standards Codification

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Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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Amount of direct write-downs of financing receivables charged against the allowance.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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