XML 45 R47.htm IDEA: XBRL DOCUMENT v2.4.1.9
Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
 1 Months Ended 12 Months Ended 1 Months Ended 14 Months Ended 1 Months Ended 3 Months Ended 1 Months Ended
Jul. 31, 2014
Oct. 31, 2013
Dec. 31, 2014
Segment
Dec. 31, 2013
Dec. 31, 2012
Apr. 30, 2013
Aug. 31, 2014
Feb. 28, 2015
Dec. 31, 2014
Dec. 31, 2011
May 31, 2014
Nov. 30, 2008
Nov. 30, 2009
Apr. 01, 2009
Class of Warrant or Right [Line Items]                            
Number of segments     1us-gaap_NumberOfOperatingSegments                      
Accumulated deficit     $ (420,271,608)us-gaap_RetainedEarningsAccumulatedDeficit $ (387,530,334)us-gaap_RetainedEarningsAccumulatedDeficit         $ (420,271,608)us-gaap_RetainedEarningsAccumulatedDeficit          
Maturity period for money market and highly liquid investments     90 days                      
Aggregate purchase price                           5,135,000stem_BusinessAcquisitionCostOfAcquiredEntityPurchasePriceNet
Percentage of purchase price allocated to goodwill     42.00%stem_BusinessAcquisitionGoodwillAsPercentageOfPurchasePrice                      
Impairment of Goodwill     1,910,062us-gaap_GoodwillImpairmentLoss                      
Other intangible assets, net     356,889us-gaap_IntangibleAssetsNetExcludingGoodwill 1,835,717us-gaap_IntangibleAssetsNetExcludingGoodwill         356,889us-gaap_IntangibleAssetsNetExcludingGoodwill          
Impairment amount of intangible asset     530,000stem_ImpairmentsOfIntangibleAssetFiniteLived           530,000stem_ImpairmentsOfIntangibleAssetFiniteLived 655,000stem_ImpairmentsOfIntangibleAssetFiniteLived        
Value of patent     0stem_ContinuingValueOfPatent                      
Fair value of certain lab equipment     0us-gaap_TangibleAssetImpairmentCharges 0us-gaap_TangibleAssetImpairmentCharges 28,000us-gaap_TangibleAssetImpairmentCharges                  
Proceeds from loan     5,775,543us-gaap_ProceedsFromLoans                      
Cash discount     100,000us-gaap_DebtInstrumentUnamortizedDiscount           100,000us-gaap_DebtInstrumentUnamortizedDiscount          
Term of loan     3 years                      
Annual interest rate on loan     6.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage           6.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage          
Final fee payment at the end of loan term     1,000,000stem_LoanFees                      
Exercise price of warrants $ 2.17us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 $ 1.80us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1                        
Initial carrying amount assigned to loan, net of discount     9,512,000stem_CarryingValueOfPurchasedLoans           9,512,000stem_CarryingValueOfPurchasedLoans          
Fair value allocated to warrant     388,000stem_FairValueAllocatedToWarrant           388,000stem_FairValueAllocatedToWarrant          
Note issuance costs     117,000us-gaap_DebtIssuanceCosts                      
Deferred financing costs, discount and accretion percentage     9.00%stem_DebtInstrumentAmortizedDiscountPercentage                      
Common stock per unit     $ 1stem_CommonStockPerUnit                      
Warrants issued per unit     $ 1stem_WarrantsIssuedPerUnit                      
Number of shares issued upon Series B warrants exercise 11,299,435us-gaap_StockIssuedDuringPeriodSharesNewIssues 12,845,500us-gaap_StockIssuedDuringPeriodSharesNewIssues                        
CIRM [Member]                            
Class of Warrant or Right [Line Items]                            
Proceeds from loan     5,775,543us-gaap_ProceedsFromLoans
/ us-gaap_TypeOfArrangementAxis
= stem_CaliforniaInstituteForRegenerativeMedicineMember		                      
Approval of fund by California Institute for Regenerative Medicine (CIRM)           19,300,000stem_ApprovalOfFundToCollaborators
/ us-gaap_TypeOfArrangementAxis
= stem_CaliforniaInstituteForRegenerativeMedicineMember		                
Aggregate proceeds from disbursement of the loan             9,600,000us-gaap_ProceedsFromIssuanceOfDebt
/ us-gaap_TypeOfArrangementAxis
= stem_CaliforniaInstituteForRegenerativeMedicineMember		              
Forgiveness of loan principal     8,917,000us-gaap_DebtInstrumentDecreaseForgiveness
/ us-gaap_TypeOfArrangementAxis
= stem_CaliforniaInstituteForRegenerativeMedicineMember		                      
Accrued interest forgiven     243,000us-gaap_DebtInstrumentIncreaseAccruedInterest
/ us-gaap_TypeOfArrangementAxis
= stem_CaliforniaInstituteForRegenerativeMedicineMember		                      
CIRM [Member] | Subsequent Events [Member]                            
Class of Warrant or Right [Line Items]                            
Repayment of aggregate loan proceeds received               679,000us-gaap_RepaymentsOfDebt
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
/ us-gaap_TypeOfArrangementAxis
= stem_CaliforniaInstituteForRegenerativeMedicineMember		            
Silicon Valley Bank [Member]                            
Class of Warrant or Right [Line Items]                            
Proceeds from loan            9,900,000us-gaap_ProceedsFromLoans
/ us-gaap_RelatedPartyTransactionAxis
= stem_SiliconValleyBankMember		                
Cash discount           100,000us-gaap_DebtInstrumentUnamortizedDiscount
/ us-gaap_RelatedPartyTransactionAxis
= stem_SiliconValleyBankMember		                
Common Stock [Member]                            
Class of Warrant or Right [Line Items]                            
Number of securities callable by warrants     1,180,015us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember		           1,180,015us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember		          
Warrant component 0.85us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember		 0.5us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember		                        
Outstanding Warrants [Member]                            
Class of Warrant or Right [Line Items]                            
Fair value of warrant liability     1,685,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_WarrantMember		           1,685,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_WarrantMember		          
Marketable debt securities, current [Member] | Minimum [Member]                            
Class of Warrant or Right [Line Items]                            
Investments with maturities     365 days or less                      
Marketable securities, non-current [Member] | Maximum [Member]                            
Class of Warrant or Right [Line Items]                            
Investments with maturities     Greater than 365 days                      
Stem Cell Sciences Holdings Ltd [Member]                            
Class of Warrant or Right [Line Items]                            
Aggregate purchase price                           5,135,000stem_BusinessAcquisitionCostOfAcquiredEntityPurchasePriceNet
/ us-gaap_BusinessAcquisitionAxis
= stem_StemCellSciencesHoldingsLtdMember
Percentage of purchase price allocated to goodwill                 42.00%stem_BusinessAcquisitionGoodwillAsPercentageOfPurchasePrice
/ us-gaap_BusinessAcquisitionAxis
= stem_StemCellSciencesHoldingsLtdMember		          
Impairment of Goodwill                 $ 1,910,000us-gaap_GoodwillImpairmentLoss
/ us-gaap_BusinessAcquisitionAxis
= stem_StemCellSciencesHoldingsLtdMember		          
Silicon Valley Bank Loan Agreement Warrant [Member]                            
Class of Warrant or Right [Line Items]                            
Term of warrant     10 years                      
Exercise price of warrants     $ 1.7034us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SiliconValleyBankLoanAgreementWarrantMember		           $ 1.7034us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SiliconValleyBankLoanAgreementWarrantMember		          
Warrant expiration period     April 2023                      
Silicon Valley Bank Loan Agreement Warrant [Member] | Common Stock [Member]                            
Class of Warrant or Right [Line Items]                            
Number of securities callable by warrants     293,531us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SiliconValleyBankLoanAgreementWarrantMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember		           293,531us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SiliconValleyBankLoanAgreementWarrantMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember		          
December 2011 Financing [Member] | Common Stock [Member]                            
Class of Warrant or Right [Line Items]                            
Warrant component     1us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		           1us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		          
Number of shares issued upon Series B warrants exercise       384,534us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		 2,700,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		                  
December 2011 Financing [Member] | Series A Warrants [Member]                            
Class of Warrant or Right [Line Items]                            
Term of warrant                   5 years        
Number of securities callable by warrants                   8,000,000us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SeriesAWarrantsMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		        
Warrant component     1us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SeriesAWarrantsMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		           1us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SeriesAWarrantsMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		          
Number of warrants issued upon Series B warrants exercise         2,700,000stem_ClassOfWarrantOrRightNumberOfWarrantsOrRightsIssued
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SeriesAWarrantsMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		                  
December 2011 Financing [Member] | Series A Warrants [Member] | Common Stock [Member]                            
Class of Warrant or Right [Line Items]                            
Exercise price of warrants                   1.40us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SeriesAWarrantsMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		        
December 2011 Financing [Member] | Series B Warrants [Member]                            
Class of Warrant or Right [Line Items]                            
Term of warrant                   90 days        
Number of securities callable by warrants                   8,000,000us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SeriesBWarrantsMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		        
Exercise price of warrants                   1.25us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SeriesBWarrantsMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		        
Number of warrants exercised         2,700,000stem_ClassOfWarrantOrRightNumberOfWarrantsOrRightsExercised
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SeriesBWarrantsMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		                  
Number of warrants expired         5,300,000stem_ClassOfWarrantOrRightNumberOfWarrantsOrRightsExpired
/ us-gaap_ClassOfWarrantOrRightAxis
= stem_SeriesBWarrantsMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_DecemberTwoThousandElevenFinancingMember		                  
November 2008 Financing [Member]                            
Class of Warrant or Right [Line Items]                            
Warrants issued                     1,034,483stem_ClassOfWarrantOrRightIssued
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_NovemberTwoThousandEightFinancingMember		      
November 2008 Financing [Member] | Common Stock [Member]                            
Class of Warrant or Right [Line Items]                            
Number of securities callable by warrants                       1,034,483us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_NovemberTwoThousandEightFinancingMember		    
Exercise price of warrants                       23.00us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_NovemberTwoThousandEightFinancingMember		    
Warrant component                       0.75us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_NovemberTwoThousandEightFinancingMember		    
November 2008 Financing [Member] | Outstanding Warrants [Member]                            
Class of Warrant or Right [Line Items]                            
Term of warrant                       5 years    
November 2009 Financing [Member]                            
Class of Warrant or Right [Line Items]                            
Exercise price of warrants     $ 15.00us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_NovemberTwoThousandNineFinancingMember		           $ 15.00us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_NovemberTwoThousandNineFinancingMember		          
November 2009 Financing [Member] | Common Stock [Member]                            
Class of Warrant or Right [Line Items]                            
Number of securities callable by warrants                         400,000us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_NovemberTwoThousandNineFinancingMember		  
Exercise price of warrants                         15.00us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_NovemberTwoThousandNineFinancingMember		  
Warrant component                         0.40us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
/ us-gaap_SubsidiarySaleOfStockAxis
= stem_NovemberTwoThousandNineFinancingMember		  
November 2009 Financing [Member] | Outstanding Warrants [Member]                            
Class of Warrant or Right [Line Items]                            
Term of warrant                         5 years