Annual report pursuant to Section 13 and 15(d)

Common Stock - Additional Information (Detail)

v2.4.1.9
Common Stock - Additional Information (Detail) (USD $)
0 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended
Jul. 25, 2014
Nov. 22, 2013
Oct. 31, 2013
Sep. 30, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2010
Nov. 30, 2009
Dec. 31, 2012
Nov. 07, 2014
Aug. 31, 2006
Dec. 31, 2004
Dec. 31, 2003
Apr. 30, 2007
Class of Stock [Line Items]                            
Common stock, shares authorized         100,000,000us-gaap_CommonStockSharesAuthorized 100,000,000us-gaap_CommonStockSharesAuthorized                
Issuance of common stock upon conversion of redeemable convertible preferred stock       2,793,281us-gaap_ConversionOfStockSharesIssued1                    
Conversion of preferred stock to common stock       $ 320,000,000us-gaap_ConversionOfStockAmountIssued1   $ 323,155,000us-gaap_ConversionOfStockAmountIssued1                
Common stock shares sold   604,000us-gaap_CommonStockSharesIssued 664,300us-gaap_CommonStockSharesIssued 5,366,669us-gaap_CommonStockSharesIssued 14,696,108us-gaap_CommonStockSharesIssued 9,455,064us-gaap_CommonStockSharesIssued                
Warrants to purchase shares of common stock in private placement   120,800cyma_WarrantsToPurchaseOfCommonStockShares 132,860cyma_WarrantsToPurchaseOfCommonStockShares 1,073,338cyma_WarrantsToPurchaseOfCommonStockShares                    
Net proceeds from issuance of private placement     2,200,000cyma_NetProceedsFromIssuanceOfPrivatePlacement 22,800,000cyma_NetProceedsFromIssuanceOfPrivatePlacement                    
Loan facility extinguished in exchange of common stock       624,944us-gaap_DebtConversionConvertedInstrumentSharesIssued1                    
Amount of debt cancelled upon issuance of common stock shares       16,900,000cyma_StockIssuedDuringPeriodAmountForCancellationOfDebt                    
Net proceeds from issuance of private placement   2,700,000us-gaap_ProceedsFromIssuanceOfPrivatePlacement   26,800,000us-gaap_ProceedsFromIssuanceOfPrivatePlacement                    
Common stock shares sold 4,600,000us-gaap_StockIssuedDuringPeriodSharesNewIssues                          
Common stock offering price $ 5.50us-gaap_SharesIssuedPricePerShare                   $ 365.70us-gaap_SharesIssuedPricePerShare      
Net proceeds from public offering 23,000,000us-gaap_ProceedsFromIssuanceInitialPublicOffering                          
Registration filed on Form S-3                   100,000,000us-gaap_RegistrationPaymentArrangementMaximumPotentialConsideration        
Registration statement, event description         Entered into an at-the-market facility (ATM) to sell up to $25 million of common stock under the registration statement.                  
Registration statement, sale of common stock                   25,000,000cyma_RegistrationPaymentArrangementCommonStockValue        
Change in fair value of warrant liability         7,236,000us-gaap_FairValueAdjustmentOfWarrants 494,000us-gaap_FairValueAdjustmentOfWarrants                
Percentage of reduction in number of shares exercisable             50.00%cyma_WarrantsExercisableDecreasedPercentage              
Number of warrants outstanding             14,623us-gaap_ClassOfWarrantOrRightOutstanding              
Warrants, Exercise price of $5.75 per share [Member]                            
Class of Stock [Line Items]                            
Issued warrants to purchase common stock           1,741,788us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_ClassOfWarrantOrRightAxis
= cyma_WarrantsOneMember
               
Exercise of price of common stock           $ 5.75us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= cyma_WarrantsOneMember
               
Warrant term           5 years                
Warrants, Exercise price of $5.00 per share [Member]                            
Class of Stock [Line Items]                            
Issued warrants to purchase common stock           121,739us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_ClassOfWarrantOrRightAxis
= cyma_WarrantsTwoMember
               
Exercise of price of common stock       $ 5.00us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= cyma_WarrantsTwoMember
  $ 5.00us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= cyma_WarrantsTwoMember
               
Warrant term           5 years                
At The Market Facility [Member]                            
Class of Stock [Line Items]                            
Common stock shares sold         0us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_SubsidiarySaleOfStockAxis
= cyma_AtTheMarketFacilityMember
                 
Series B-1 Preferred [Member]                            
Class of Stock [Line Items]                            
Common stock offering price         $ 232.93us-gaap_SharesIssuedPricePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
            $ 232.93us-gaap_SharesIssuedPricePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
$ 232.93us-gaap_SharesIssuedPricePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
 
Issued warrants to purchase common stock               29,245us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
      29,245us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
   
Exercise of price of common stock                       $ 30.21us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
   
Warrant, extended expiration date               Dec. 31, 2011 Apr. 01, 2013          
Percentage of reduction in number of shares exercisable                 45.00%cyma_WarrantsExercisableDecreasedPercentage
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
         
Number of warrants outstanding                 13,160us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
         
Share price per share                       $ 1.51us-gaap_SharePrice
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
   
Series B-1 Preferred [Member] | Period One [Member]                            
Class of Stock [Line Items]                            
Warrant, extended expiration date               Dec. 31, 2010            
Series B-1 Preferred [Member] | Scenario, Previously Reported [Member]                            
Class of Stock [Line Items]                            
Percentage of reduction in number of shares exercisable                 45.00%cyma_WarrantsExercisableDecreasedPercentage
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
         
Number of warrants outstanding                 13,163us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioPreviouslyReportedMember
         
Series D-1 Preferred [Member]                            
Class of Stock [Line Items]                            
Common stock offering price         $ 232.94us-gaap_SharesIssuedPricePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesDPreferredStockMember
                $ 232.94us-gaap_SharesIssuedPricePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesDPreferredStockMember
Issued warrants to purchase common stock                           20,639us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesDPreferredStockMember
Exercise of price of common stock                           $ 22.13us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesDPreferredStockMember
Change in fair value of warrant liability             100,000us-gaap_FairValueAdjustmentOfWarrants
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesDPreferredStockMember
             
Warrant, extended expiration date             Apr. 13, 2013              
Share price per share                           $ 0.79us-gaap_SharePrice
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesDPreferredStockMember
Series D-1 Preferred [Member] | Warrants [Member]                            
Class of Stock [Line Items]                            
Share price per share             15.90us-gaap_SharePrice
/ us-gaap_DerivativeByNatureAxis
= us-gaap_WarrantMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesDPreferredStockMember
             
Risk-free interest rate             0.50%us-gaap_FairValueAssumptionsRiskFreeInterestRate
/ us-gaap_DerivativeByNatureAxis
= us-gaap_WarrantMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesDPreferredStockMember
             
Volatility price             83.00%us-gaap_FairValueAssumptionsWeightedAverageVolatilityRate
/ us-gaap_DerivativeByNatureAxis
= us-gaap_WarrantMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesDPreferredStockMember
             
Series D-1 Preferred [Member] | Warrants [Member] | Minimum [Member]                            
Class of Stock [Line Items]                            
Expected life             1 year              
Series D-1 Preferred [Member] | Warrants [Member] | Maximum [Member]                            
Class of Stock [Line Items]                            
Expected life             2 years