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Represents the minimum percentage of likelihood of tax position being realized upon ultimate settlement, if the tax position meets the more likely than not recognition threshold.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Represents the minimum percentage of net actuarial gain (loss) to be amortized in net periodic benefit costs.

+ References

No definition available.

+ Details

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Namespace Prefix:	boh_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of Company's pension plans.

+ References

No definition available.

+ Details

Name:	boh_NumberOfPensionPlans
Namespace Prefix:	boh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

+ References

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 93-7

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 720

-SubTopic 35

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6390789&loc=d3e2420-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 144

-Paragraph 45, 46, 47

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

+ Details

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

- Details

Name:	us-gaap_MarketingAndAdvertisingExpenseAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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- Definition

The maximum useful life of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

+ References

No definition available.

+ Details

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Data Type:	xbrli:decimalItemType
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- Definition

The minimum useful life of long lived, physical assets used in the normal conduct of business and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
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Summary of Significant Accounting Policies (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 plan	Dec. 31, 2010	Dec. 31, 2009
Pension and Postretirement Benefit Plans
Number of company's pension plans	2
Minimum percentage of net acturial gain (loss) will be amortized in net periodic benefit cost	10.00%
Income Taxes
Minimum percentage of likelihood of tax position being realized upon ultimate settlement according to management's judgment	50.00%
Advertising Costs
Advertising expenses	$ 5.5	$ 5.0	$ 5.0
Premises
Premises and Equipment
Minimum estimated useful lives (in years)	5
Maximum estimated useful lives (in years)	20
Impairment charge	$ 0.6
Equipment
Premises and Equipment
Minimum estimated useful lives (in years)	3
Maximum estimated useful lives (in years)	10