XML 37 R48.htm IDEA: XBRL DOCUMENT v2.4.1.9
Convertible Notes Payable to Shareholders - Additional Information (Detail) (USD $)
0 Months Ended 1 Months Ended 3 Months Ended 12 Months Ended 0 Months Ended
Apr. 15, 2014
Apr. 30, 2014
Jun. 30, 2014
Dec. 31, 2014
Nov. 30, 2010
Mar. 31, 2014
Aug. 31, 2013
Sep. 30, 2010
May 31, 2010
Debt Instrument [Line Items]                  
Debt instrument, Original principal amount             $ 8,824,000us-gaap_DebtInstrumentFaceAmount    
Debt instrument stated interest rate           7.00%us-gaap_DebtInstrumentInterestRateStatedPercentage 7.00%us-gaap_DebtInstrumentInterestRateStatedPercentage    
Debt instrument percentage 77.50%us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger                
IPO closure date       2014-04-15          
Loss on extinguishment of debt   (2,493,000)us-gaap_GainsLossesOnExtinguishmentOfDebt (2,493,000)us-gaap_GainsLossesOnExtinguishmentOfDebt (2,493,000)us-gaap_GainsLossesOnExtinguishmentOfDebt          
Convertible Notes Payable [Member]                  
Debt Instrument [Line Items]                  
Debt instrument, Original principal amount               1,500,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
5,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
Debt instrument stated interest rate               7.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
7.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
Preferred stock shares became exercisable 60,532us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
               
Fair value of warrants         474,000us-gaap_WarrantsNotSettleableInCashFairValueDisclosure
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
       
Expected volatility         80.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
       
Expected life         7 years        
Risk-free interest rate         1.85%us-gaap_FairValueAssumptionsRiskFreeInterestRate
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
       
Dividend yield         $ 0us-gaap_FairValueAssumptionsExpectedDividendPayments
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
       
Convertible Notes Payable [Member] | Series C Convertible Preferred Stock [Member]                  
Debt Instrument [Line Items]                  
Debt instrument conversion of principal and accrued interest         176,000us-gaap_DebtConversionOriginalDebtAmount1
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesCPreferredStockMember
       
Debt instrument conversion shares         9,021,175us-gaap_DebtConversionConvertedInstrumentSharesIssued1
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesCPreferredStockMember
       
Debt instrument conversion price         $ 0.74us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesCPreferredStockMember
       
Percentage to determine the number of shares included in warrants         10.00%ceru_PercentageOfNotesConvertedInToShareToDetermineNumberOfSharesInWarrants
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesCPreferredStockMember
       
Preferred stock shares became exercisable         878,370us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesCPreferredStockMember
       
Preferred stock per share         $ 0.74us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ShortTermDebtTypeAxis
= us-gaap_ConvertibleNotesPayableMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesCPreferredStockMember
       
Convertible Promissory Notes [Member] | Existing Investors [Member]                  
Debt Instrument [Line Items]                  
Debt instrument, Original principal amount           6,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= ceru_DebtInstrumentExistingInvestorsMember
/ us-gaap_ShortTermDebtTypeAxis
= ceru_ConvertiblePromissoryNotesMember
     
Convertible Promissory Notes [Member] | New Investor [Member]                  
Debt Instrument [Line Items]                  
Debt instrument, Original principal amount           2,500,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= ceru_DebtInstrumentNewInvestorMember
/ us-gaap_ShortTermDebtTypeAxis
= ceru_ConvertiblePromissoryNotesMember