Name:	nbl_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirationPeriod
Namespace Prefix:	nbl_
Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration

The period of time during which a range of company stock prices is used to calculate an average stock price.

No definition available.

Name:	nbl_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAverageStockPricePeriodUsed
Namespace Prefix:	nbl_
Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration

The maximum term to maturity on US Treasuries used within the option valuation model to approximate a risk-free rate assumption. The risk-free rate is the implied yield on US Treasury securities with remaining term equal to the expected term of the option.

No definition available.

Name:	nbl_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsMaximumTermToMaturity
Namespace Prefix:	nbl_
Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration

The minimum term to maturity on US Treasuries used within the option valuation model to approximate a risk free rate assumption. The risk-free rate is the implied yield on US Treasury securities with remaining term equal to the expected term of the option.

No definition available.

Name:	nbl_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsMinimumTermToMaturity
Namespace Prefix:	nbl_
Data Type:	us-types:durationStringItemType
Balance Type:	na
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Name:	nbl_ShareBasedCompensationArrangementByShareBasedPaymentPlanLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
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Maximum range number of shares approved, net of any subsequent amendments and adjustments, for awards under share-based compensation plans.

No definition available.

Name:	nbl_ShareBasedCompensationArrangementByShareBasedPaymentPlanMaximumNumberOfSharesAuthorized
Namespace Prefix:	nbl_
Data Type:	xbrli:sharesItemType
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Period Type:	instant

Minimum range number of shares approved, net of any subsequent amendments and adjustments, for awards under share-based compensation plans.

No definition available.

Name:	nbl_ShareBasedCompensationArrangementByShareBasedPaymentPlanMinimumNumberOfSharesAuthorized
Namespace Prefix:	nbl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The number of option shares available for granting to a non-employee director during the first calendar year of service.

No definition available.

Name:	nbl_ShareBasedCompensationArrangementByShareBasedPaymentPlanOptionsAuthorizedForGrantFirstYearOfServicePerDirector
Namespace Prefix:	nbl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The maximum number of restricted stock units approved (usually by shareholders and board of directors) for annual and discretionary awards.

No definition available.

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Data Type:	xbrli:sharesItemType
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Period Type:	instant

The number of restricted stock units that are awarded annually to a non-employee director

No definition available.

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Namespace Prefix:	nbl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Description of restricted stock award terms as to the percentage of shares which are no longer contingent, three years after date of grant, on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert a percentage of the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

No definition available.

Name:	nbl_ShareBasedCompensationArrangementByShareBasedPaymentPlanRestrictedStockAwardsVestingRightsAfterYearThree
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Data Type:	us-types:percentItemType
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Description of restricted stock award terms as to the percentage of shares which are no longer contingent, one year after date of grant, on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert a percentage of the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

No definition available.

Name:	nbl_ShareBasedCompensationArrangementByShareBasedPaymentPlanRestrictedStockAwardsVestingRightsYearOne
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Data Type:	us-types:percentItemType
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Description of restricted stock award terms as to the percentage of shares which are no longer contingent, two years after date of grant, on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert a percentage of the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

No definition available.

Name:	nbl_ShareBasedCompensationArrangementByShareBasedPaymentPlanRestrictedStockAwardsVestingRightsYearTwo
Namespace Prefix:	nbl_
Data Type:	us-types:percentItemType
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The maximum number of option shares approved (usually by shareholders and board of directors) for annual and discretionary grants to a non-employee director.

No definition available.

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Data Type:	xbrli:sharesItemType
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Period Type:	instant

The number of option shares available for annual grants, per non-employee director, to be awarded on February 1 of each year.

No definition available.

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Namespace Prefix:	nbl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Represents the expense recognized during the period arising from share-based compensation arrangements (for example, shares of stock, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-Subparagraph b

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

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Data Type:	xbrli:monetaryItemType
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Aggregate number of common shares reserved for future issuance.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 4

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

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Data Type:	xbrli:stringItemType
Balance Type:	na
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The total recognized tax benefit related to compensation cost for share-based payment arrangements recognized in income during the period.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

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Data Type:	xbrli:monetaryItemType
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As of the latest balance-sheet date presented, the total compensation cost related to outstanding, nonvested share-based compensation awards not yet recognized (will be charged against earnings as services are performed or other vesting criteria are met).

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph h

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Data Type:	xbrli:monetaryItemType
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The weighted average period over which unrecognized share-based compensation costs are expected to be reported.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph h

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Data Type:	xbrli:decimalItemType
Balance Type:	na
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Description of the period of time over which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, which may be expressed in a variety of ways (for example, in years, month and year).

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph a

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Data Type:	xbrli:stringItemType
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The number of shares under a share-based award plan other than a stock option plan that were settled during the reporting period due to a failure to satisfy vesting conditions pertaining to all option plans.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(e)

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The weighted average fair value as of the grant date of share-based award plans other than stock option plans that were not exercised or put into effect during the reporting period as a result of the occurrence of a terminating event specified in the contractual agreement of the plan.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(e)

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Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	instant

The number of shares issuable under a share-based award plan pertaining to grants made during the period on other than stock option plans (for example, phantom stock plan, stock appreciation rights plan, performance target plan).

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(c)

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The weighted average fair value at grant for nonvested share-based awards issued during the period on other than stock option plans (for example, phantom stock plan, stock appreciation rights plan, performance target plan).

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(c)

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

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Namespace Prefix:	us-gaap_
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	duration

The number of outstanding awards on nonstock option plans (for example, phantom stock plan, stock appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(a)

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(b)

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

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Balance Type:	na
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The weighted average fair value of nonvested awards on share-based plans excluding option plans (for example, phantom stock plan, stock appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(a)

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(b)

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	instant

The decrease in the number of shares potentially issuable under a share-based award plan pertaining to awards for which the grantee has gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares, other instruments, or cash in accordance with the terms of the arrangement.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(d)

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The total fair value of share-based awards for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares, other instruments, or cash in accordance with the terms of the arrangement.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(2)

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

The weighted average fair value as of grant dates pertaining to a share-based award plan other than a stock option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares, other instruments, or cash in accordance with the terms of the arrangement.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(d)

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Namespace Prefix:	us-gaap_
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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph e(2)(c)

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Namespace Prefix:	us-gaap_
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

The period of time a share-based award is expected to be outstanding. A share-based award's expected term shall be determined based on, among other factors, the instrument's contractual term and the effects of employees' expected exercise and post-vesting employment termination behavior. An entity is required to aggregate individual awards into relatively homogeneous groups.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph e(2)(a)

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section D

-Subsection 2

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The estimated measure of the percentage amount by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph e(2)(b)

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Data Type:	us-types:percentItemType
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Period Type:	duration

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph e(2)(d)

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Data Type:	us-types:percentItemType
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The difference between the maximum number of shares authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares already issued upon exercise of options or other share-based awards under the plan, and 2) shares reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

No definition available.

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Balance Type:	na
Period Type:	instant

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The total dollar difference between fair values of the underlying shares reserved for issuance and exercise prices of vested portions of options outstanding and currently exercisable under the option plan as of the balance-sheet date.

No definition available.

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Balance Type:	debit
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The number of shares into which fully or partially vested stock options outstanding as of the balance-sheet date can be currently converted under the option plan.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(c), d(2)

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(c)

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Namespace Prefix:	us-gaap_
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	instant

The weighted average period between the balance-sheet date and expiration for all vested portions of options outstanding and currently exercisable (or convertible) under the plan, which may be expressed in a decimal value for number of years.

No definition available.

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Data Type:	xbrli:decimalItemType
Balance Type:	na
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The decrease in the number of reserved shares that could potentially be issued attributable to the exercise or conversion during the reporting period of previously issued stock options under the option plan.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(e)

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(2)

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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The weighted average price at which option holders acquired shares when converting their stock options into shares under the plan during the reporting period.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(e)

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Namespace Prefix:	us-gaap_
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	instant

For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod
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Data Type:	xbrli:sharesItemType
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The weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated during the reporting period due to noncompliance with plan terms during the reporting period.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(f)

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Namespace Prefix:	us-gaap_
Data Type:	us-types:perShareItemType
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Period Type:	instant

The quantity of shares issuable on stock options awarded under the plan during the reporting period.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(d)

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The weighted average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on stock options awarded under the plan during the reporting period.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(d)

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Namespace Prefix:	us-gaap_
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	instant

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

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Namespace Prefix:	us-gaap_
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	duration

The total dollar difference between fair values of the underlying shares reserved for issuance and exercise prices pertaining to options outstanding under the plan as of the balance-sheet date.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph d(1)

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance-sheet date, including vested options.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(a)

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(b)

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

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

The weighted average price as of the beginning of the year at which grantees can acquire the shares reserved for issuance under the stock option plan.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(a)

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Namespace Prefix:	us-gaap_
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	instant

The weighted average period between the balance-sheet date and expiration for all awards outstanding under the plan, which may be expressed in a decimal value for number of years.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph a