Name:	gern_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumExercisePriceOfOptionsGrantedToEmployeesWithMoreThan10PercentageOfCommonStock
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Represents the minimum percentage of ownership required for granting of options at a price not less than 110 percent of the fair market value of common stock.

No definition available.

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Aggregate Intrinsic Value

No definition available.

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Represents the number of options to be granted to purchase shares in each year during the optionee's service on the Board of Directors.

No definition available.

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Represents the number of options to be granted to purchase shares upon appointment to Board of Directors.

No definition available.

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Represents the maximum expiration term of options granted to employees having more than 10 % outstanding common stock.

No definition available.

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Aggregate number of common shares reserved for future issuance.

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Amount of cash inflow from exercise of option under share-based payment arrangement.

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Period Type:	duration

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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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/disclosureRef
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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/disclosureRef
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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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The addition or reduction in the number of reserved shares that could potentially be issued under the option plan attributable to reasons other than grants, exercises, forfeitures, and expirations during the reporting period.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- References

No definition available.

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Price of a single share of a number of saleable stocks of a company.

No definition available.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of shares issued in lieu of cash for services contributed to the entity. Number of shares includes, but is not limited to, shares issued for services contributed by vendors and founders.

No definition available.

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