Name:	gern_AccruedClinicalResearchOrganizationsAndClinicalTrialCostsCurrent
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Carrying value as of the balance sheet of obligations incurred through the date and payable for manufacturing related costs. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

No definition available.

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Gross To Net Adjustments, Current

No definition available.

Name:	gern_GrossToNetAdjustmentsCurrent
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Data Type:	xbrli:monetaryItemType
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Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(20))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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Carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Data Type:	xbrli:monetaryItemType
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Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

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Data Type:	xbrli:monetaryItemType
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- References

No definition available.