XML 27 R16.htm IDEA: XBRL DOCUMENT v3.4.0.3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - MARKETABLE SECURITIES AND USEFUL LIVES OF ASSETS (Details)	3 Months Ended
	Mar. 31, 2016
Depreciation and Amortization
Estimated useful lives of assets	4 years
Minimum
Marketable securities
Original maturity period of marketable securities	4 months
Maximum
Marketable securities
Original maturity period of marketable securities	24 months

X

- Definition

Represents the original maturity period of securities, which are categorized neither as held-to-maturity nor trading.

+ References

No definition available.

+ Details

Name:	gern_AvailableForSaleSecuritiesOriginalMaturityPeriod
Namespace Prefix:	gern_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

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

X

- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

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.

+ References

No definition available.

+ Details

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

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: