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STOCKHOLDERS' EQUITY (Details) (USD $)
0 Months Ended 12 Months Ended 1 Months Ended
Feb. 04, 2014
Dec. 31, 2014
Dec. 31, 2014
Warrants      
Class of Warrant or Right, Outstanding   1,007,893us-gaap_ClassOfWarrantOrRightOutstanding 1,007,893us-gaap_ClassOfWarrantOrRightOutstanding
Underwritten Public Offering      
Underwritten public offering (in shares) 25,875,000us-gaap_StockIssuedDuringPeriodSharesNewIssues    
Public offering price (in dollars per share) $ 4.00gern_EquityIssuancePerShareAmountAtPublicOffering    
Net cash proceeds from public offering after deducting the underwriting discount and offering expenses $ 96,805,000us-gaap_StockIssuedDuringPeriodValueNewIssues $ 96,805,000us-gaap_StockIssuedDuringPeriodValueNewIssues  
Warrants issued in August 2011      
Warrants      
Exercise Price (in dollars per share)   $ 3.98us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= gern_WarrantsIssuedInAugust2011Member
3.98us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= gern_WarrantsIssuedInAugust2011Member
Class of Warrant or Right, Outstanding   537,893us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= gern_WarrantsIssuedInAugust2011Member
537,893us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= gern_WarrantsIssuedInAugust2011Member
Warrants issued in April 2005      
Warrants      
Exercise Price (in dollars per share)   $ 3.75us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= gern_WarrantsIssuedInApril2005Member
3.75us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= gern_WarrantsIssuedInApril2005Member
Class of Warrant or Right, Outstanding   470,000us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= gern_WarrantsIssuedInApril2005Member
470,000us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= gern_WarrantsIssuedInApril2005Member
CIRM | Warrants issued in November 2011      
Warrants      
Number of warrants net exercised     461,382gern_NumberOfWarrantsNetExcercised
/ us-gaap_ClassOfWarrantOrRightAxis
= gern_WarrantsIssuedInNovember2011Member
/ dei_LegalEntityAxis
= gern_CaliforniaInstituteForRegenerativeMedicineMember
Issuance of common stock upon net exercise of warrants (in shares)     168,039gern_StockIssuedDuringPeriodSharesNetExerciseOfWarrants
/ us-gaap_ClassOfWarrantOrRightAxis
= gern_WarrantsIssuedInNovember2011Member
/ dei_LegalEntityAxis
= gern_CaliforniaInstituteForRegenerativeMedicineMember