Organization and Description of Business	12 Months Ended
Organization and Description of Business	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	ORGANIZATION AND DESCRIPTION OF BUSINESS CareDx, Inc. (“CareDx” or the “Company”) together with its subsidiaries, is a leading precision medicine company focused on the discovery, development and commercialization of clinically differentiated, high-value healthcare solutions for transplant patients and caregivers. The Company’s headquarters are in South San Francisco, California. The primary operations are in Brisbane, California; Omaha, Nebraska; Fremantle, Australia and Stockholm, Sweden. The Company’s commercially available testing services consist of AlloSure Kidney, which is a donor-derived cell-free DNA (“dd-cfDNA”) solution for kidney transplant patients, and AlloMap Heart, which is a gene expression solution for heart transplant patients. The Company also offers high quality products that increase the chance of successful transplants by facilitating a better match between a donor and a recipient of stem cells and organs. In 2019, the Company began providing digital solutions to transplant centers following the acquisitions of Ottr Complete Transplant Management (“OttrCare”) and XynManagement, Inc. (“XynManagement”). Testing Services In October 2017, the Company commercially launched AlloSure Kidney, its proprietary next generation sequencing-based test that measures dd-cfDNA in kidney transplant recipients. The Medicare reimbursement rate for AlloSure Kidney is currently $2,841. AlloSure Kidney has also received payment from private payers on a case-by-case basis, with the first private payer, BCBS of South Carolina, issuing a positive coverage decision in its October 2019 review. AlloMap Heart is a covered service for Medicare beneficiaries since January 1, 2006. The Medicare reimbursement rate for AlloMap Heart is currently $3,240. AlloMap Heart has also received positive coverage decisions from many of the largest U.S. private payers. In January 2018, the Company initiated the Kidney Allograft Outcomes AlloSure Kidney Registry study ("K-OAR"), to develop further data on the clinical utility of AlloSure Kidney for surveillance of kidney transplant recipients. K-OAR is a multicenter, non-blinded, prospective observational cohort study which plans to enroll greater than 1,500 renal transplant patients who will receive AlloSure Kidney long-term surveillance. In September 2019, the Company announced the commencement of the Outcomes of KidneyCare on Renal Allografts (“OKRA”) study, which is an extension of K-OAR. OKRA is a prospective, multi-center, observational, registry of patients receiving KidneyCare for surveillance. KidneyCare combines the dd-cfDNA analysis of AlloSure Kidney with the gene expression profiling technology of AlloMap Kidney and the predictive artificial intelligence technology of KidneyCare iBox developing a multimodality surveillance solution. The Company has not yet made any applications to payers for reimbursement coverage of AlloMap Kidney or KidneyCare iBox. In September 2018, the Company initiated the Surveillance HeartCare Outcomes Registry (“SHORE”). SHORE is a prospective, multi-center, observational registry of patients receiving HeartCare for surveillance. HeartCare combines the gene expression profiling technology of AlloMap Heart with the dd-cfDNA analysis of AlloSure Heart in one surveillance solution. In August 2019, AlloSure Heart received a positive draft Local Coverage Determination (dLCD) for Medicare coverage. In February 2019, AlloSure Lung became available for lung transplant patients through a compassionate use program while the test is undergoing further studies. Products TruSight HLA is a next generation sequencing (“NGS”)-based high-resolution typing solution that provides NGS-level resolution to HLA typing. The Company’s suite of AlloSeq products are commercial NGS-based kitted solutions that the Company acquired as a result of its license agreement with Illumina. These products include: AlloSeq Tx, a high-resolution HLA typing solution, AlloSeq cfDNA, a surveillance solution designed to measure dd-cfDNA in blood to detect active rejection in transplant recipients, and AlloSeq HCT, a solution for chimerism testing for stem cell transplant recipients. Olerup SSP is used to type Human Leukocyte Antigen (“HLA”) alleles, based on the sequence specific primer (“SSP”) technology. Olerup SBT is a complete product range for sequence-based typing of HLA alleles. QTYPE enables HLA typing at a low to intermediate resolution for samples that require a fast turnaround time and uses real-time polymerase chain reaction, or PCR methodology. Digital and Other Following the acquisitions of both OttrCare and XynManagement, the Company is a leading provider of transplant patient tracking software (“Ottr software”), as well as of transplant quality tracking and waitlist management solutions. Ottr software provides comprehensive solutions for transplant patient management and enables integration with electronic medical record ("EMR") systems providing patient surveillance management tools and outcomes data to transplant centers. XynManagement provides two unique solutions, XynQAPI software (“XynQAPI”) and Waitlist Management. XynQAPI simplifies transplant quality tracking and Scientific Registry of Transplant Recipients (“SRTR”) reporting. Waitlist Management includes a team of transplant assistants who maintain regular contact with patients on the waitlist to help prepare for their transplant and maintain eligibility. The Company's software solutions are currently used in 84 transplant centers in the U.S. Liquidity and Going Concern The Company has incurred significant losses and negative cash flows from operations since its inception and had an accumulated deficit of $333.8 million at December 31, 2019. As of December 31, 2019, the Company had cash and cash equivalents of $38.2 million. The Company may require additional financing in the future to fund working capital and the Company’s future products development. Additional financing might include issuance of equity securities, debt, or cash. There can be no assurance that the Company will be successful in acquiring additional funding at levels sufficient to fund its operations or on terms favorable to the Company. The Company believes its existing cash balance and expected revenues will be sufficient to meet its anticipated cash requirements for the next 12 months.