v2.4.1.9
Collaboration and Licensing Agreements - Additional Information (Detail)
 1 Months Ended 12 Months Ended 0 Months Ended 1 Months Ended 3 Months Ended 12 Months Ended
Jul. 31, 2013
USD ($)
Jun. 30, 2013
USD ($)
Jun. 30, 2013
EUR (€)
Dec. 31, 2014
USD ($)
Dec. 31, 2013
USD ($)
Dec. 31, 2012
USD ($)
Dec. 31, 2014
Up-front Payment Arrangement [Member]
USD ($)
Sep. 18, 2014
Laboratory Corp of America Holdings [Member]
USD ($)
Apr. 30, 2012
Laboratory Corp of America Holdings [Member]
USD ($)
Dec. 31, 2014
Laboratory Corp of America Holdings [Member]
USD ($)
Dec. 31, 2014
Laboratory Corp of America Holdings [Member]
USD ($)
Dec. 31, 2013
Laboratory Corp of America Holdings [Member]
USD ($)
Dec. 31, 2012
Laboratory Corp of America Holdings [Member]
USD ($)
Jun. 30, 2013
Diaxonhit (DHT) [Member]
USD ($)
Jun. 30, 2013
Diaxonhit (DHT) [Member]
EUR (€)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]                              
Consideration of arrangement of license                 $ 1,000,000cdna_CollaborativeAgreementContractValue
/ dei_LegalEntityAxis
= cdna_LaboratoryCorpOfAmericaHoldingsMember		            
Description of agreement expire term       The agreement will expire at the later of the last-to-expire patent in the EEA or ten years from the first commercial sale of the test in the EEA, which is expected to occur in late 2014 or early 2015.             The license term in the 2012 Agreement was the later of 10 years from the date of the agreement or the expiration of the last-to-expire patents and patent applications included in the CareDx technology licensed to LabCorp, unless the license were terminated by mutual agreement.        
Upfront license fee payment           1,000,000us-gaap_ProceedsFromLicenseFeesReceived                  
Non-refundable and non creditable payment received           250,000us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersCompensationEarned                  
Termination of collaboration agreement date                     Sep. 18, 2014        
Research and development expenses       3,846,000us-gaap_ResearchAndDevelopmentExpense 3,176,000us-gaap_ResearchAndDevelopmentExpense 4,752,000us-gaap_ResearchAndDevelopmentExpense   500,000us-gaap_ResearchAndDevelopmentExpense
/ dei_LegalEntityAxis
= cdna_LaboratoryCorpOfAmericaHoldingsMember		     32,000us-gaap_ResearchAndDevelopmentExpense
/ dei_LegalEntityAxis
= cdna_LaboratoryCorpOfAmericaHoldingsMember		 282,000us-gaap_ResearchAndDevelopmentExpense
/ dei_LegalEntityAxis
= cdna_LaboratoryCorpOfAmericaHoldingsMember		 499,000us-gaap_ResearchAndDevelopmentExpense
/ dei_LegalEntityAxis
= cdna_LaboratoryCorpOfAmericaHoldingsMember		    
Previously unrecognized license fee       505,000us-gaap_DeferredRevenueCurrent 80,000us-gaap_DeferredRevenueCurrent   611,000us-gaap_DeferredRevenueCurrent
/ us-gaap_DeferredRevenueArrangementTypeAxis
= us-gaap_UpFrontPaymentArrangementMember		                
Termination agreement fee       500,000cdna_TerminationFee 0cdna_TerminationFee 0cdna_TerminationFee       500,000cdna_TerminationFee
/ dei_LegalEntityAxis
= cdna_LaboratoryCorpOfAmericaHoldingsMember		          
Revenue recognized under collaboration and licensing agreements       1,100,000us-gaap_LicensesRevenue 328,000us-gaap_LicensesRevenue 437,000us-gaap_LicensesRevenue                  
Amortization of upfront license fee       626,000us-gaap_AmortizationOfDeferredLeasingFees 187,000us-gaap_AmortizationOfDeferredLeasingFees 187,000us-gaap_AmortizationOfDeferredLeasingFees                  
Reimbursement of research and development expenses       16,000us-gaap_ReimbursementRevenue 141,000us-gaap_ReimbursementRevenue 250,000us-gaap_ReimbursementRevenue                  
Upfront cash payment   503,000cdna_UpfrontPaymentInCash 387,500cdna_UpfrontPaymentInCash                        
Refundable upfront payments   344,000cdna_PotentialRefundablePortionOfUpfrontPayment 250,000cdna_PotentialRefundablePortionOfUpfrontPayment                        
Common stock value       12,000us-gaap_CommonStockValue 1,000us-gaap_CommonStockValue                 503,000us-gaap_CommonStockValue
/ dei_LegalEntityAxis
= cdna_DiaxonhitMember		 387,500us-gaap_CommonStockValue
/ dei_LegalEntityAxis
= cdna_DiaxonhitMember
Shares sold for consideration 467,000us-gaap_SaleOfStockConsiderationReceivedOnTransaction                            
Revenue recognized from the arrangement       36,000us-gaap_RecognitionOfDeferredRevenue                      
Royalty revenues       221,000us-gaap_RoyaltyRevenue 94,000us-gaap_RoyaltyRevenue 34,000us-gaap_RoyaltyRevenue                  
Royalty revenues receivable balance       $ 54,000cdna_RoyaltyRevenueReceivable $ 37,000cdna_RoyaltyRevenueReceivable