Name:	boch_InterestExpenseTime250000OrMore
Namespace Prefix:	boch_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Interest expense incurred on time deposits, including certificates of deposits, less than $100,000 in domestic offices.

No definition available.

Name:	boch_InterestExpenseTimeDepositsLessThan250000
Namespace Prefix:	boch_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

Name:	boch_Note11DepositsDetailsInterestExpenseforEachDepositTypeLineItems
Namespace Prefix:	boch_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Interest expense incurred on demand deposit accounts that represent borrowings rather than outstanding drafts.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.6)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Name:	us-gaap_InterestExpenseDemandDepositAccounts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Aggregate amount of interest expense on all deposits.

Name:	us-gaap_InterestExpenseDeposits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Interest expense incurred on all money market deposits.

Name:	us-gaap_InterestExpenseMoneyMarketDeposits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Interest expense incurred on all savings account deposits.