Organization and Description of Business	3 Months Ended
Mar. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Description of Business	1. ORGANIZATION AND DESCRIPTION OF BUSINESS CareDx, Inc. (“CareDx” or the “Company”) together with its subsidiaries, is a global transplant diagnostics company with product offerings along the pre- and post-transplant continuum. The Company focuses on discovery, development and commercialization of clinically differentiated, high-value diagnostic surveillance solutions for transplant patients. In post-transplant diagnostics, the Company offers AlloMap®, which is a heart transplant molecular test and AlloSure®, which is a donor-derived cell free DNA (“dd-cfDNA”) test initially used for kidney transplant patients. In pre-transplant diagnostics, the Company 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. AlloMap is a gene expression test that helps clinicians monitor and identify heart transplant recipients with stable graft function who have a low probability of moderate to severe acute cellular rejection. Since 2008, the Company has sought to expand the adoption and utilization of its AlloMap solution through ongoing studies to substantiate the clinical utility and actionability of AlloMap, secure positive reimbursement decisions for AlloMap from large private and public payers, develop and enhance its relationships with key members of the transplant community, including opinion leaders at major transplant centers, and explore opportunities and technologies for the development of additional solutions for post-transplant surveillance. The Company believes the use of AlloMap, in conjunction with other clinical indicators, can help healthcare providers and their patients better manage long-term care following a heart transplant. In particular, the Company believes AlloMap can improve patient care by helping healthcare providers avoid the use of unnecessary, invasive surveillance biopsies and determine the appropriate dosage levels of immunosuppressants. AlloMap has received 510(k) clearance from the U.S. Food and Drug Administration (the “FDA”) for marketing and sale as a test to aid in the identification of recipients with a low probability of moderate or severe acute cellular rejection. A 510(k) submission is a premarketing submission made to the FDA. Clearance may be granted by the FDA if it finds the device or test provides satisfactory evidence pertaining to the claimed intended uses and indications for the device or test. On October 9, 2017, the Company commercially launched AlloSure, its proprietary next-generation sequencing-based test to measure dd-cfDNA after transplantation. The Company believes the use of AlloSure, in conjunction with other clinical indicators, can help healthcare providers and their patients better manage long-term care following a kidney transplant. In particular, the Company believes AlloSure can improve patient care by helping healthcare providers to reduce the use of invasive biopsies and determine the appropriate dosage levels of immunosuppressants. The Company also develops, manufactures, markets and sells products that increase the chance of successful transplants by facilitating a better match between a donor and a recipient of stem cells and organs. Olerup SSP® is used to type Human Leukocyte Antigen, or HLA alleles, based on the sequence specific primer, or SSP technology. Olerup SBT^TM is a complete product range for sequence-based typing, of HLA alleles. Olerup QTYPE® enables speed and precision in HLA typing at a low to intermediate resolution for samples that require a fast turn-around-time and uses real-time polymerase chain reaction, or PCR methodology. QTYPE received CE mark certification on April 10, 2018. On May 4, 2018, the Company entered into a License and Commercialization Agreement with Illumina, Inc. (“Illumina”), which provides the Company with worldwide distribution, development and commercialization rights to Illumina’s next generation sequencing (“NGS”) product line for use in transplantation diagnostic testing. See Note 17 for further details. The Company’s headquarters are in Brisbane, California; primary operations are in Brisbane, U.S. and Stockholm, Sweden; and the Company operates in two reportable segments. 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 $274.1 million at March 31, 2018. As of March 31, 2018, the Company had cash and cash equivalents of $18.7 million, and $10.2 million of debt outstanding under its debt obligations, of which $0.5 million is current. On April 17, 2018, the Company entered into a new credit agreement with Perceptive Credit Holdings II, LP (“Perceptive”) for an initial term loan of $15.0 million and repaid the outstanding indebtedness of the promissory notes issued by Allenex AB (“Allenex”) to FastPartner AB and Mohammed Al Moudi and the term loan and credit facility with Danske Bank A/S (“Danske”). A second tranche of $10.0 million will be available at the Company’s option subject to the satisfaction of customary conditions. Refer to Note 17 for additional details. The Company may require additional financing in the future to fund working capital and pay its obligations as they come due. Additional financing might include one or more offerings and one or more of a combination of equity securities, debt arrangements or collaborations. However, 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 that the net proceeds from the Perceptive refinancing, as well as its existing cash balance and expected revenues, will be sufficient to meet its anticipated cash requirements for at least the next 12 months.

1. ORGANIZATION AND DESCRIPTION OF BUSINESS

CareDx, Inc. (“CareDx” or the “Company”) together with its subsidiaries, is a global transplant diagnostics company with product offerings along the pre- and post-transplant continuum. The Company focuses on discovery, development and commercialization of clinically differentiated, high-value diagnostic surveillance solutions for transplant patients. In post-transplant diagnostics, the Company offers AlloMap®, which is a heart transplant molecular test and AlloSure®, which is a donor-derived cell free DNA (“dd-cfDNA”) test initially used for kidney transplant patients. In pre-transplant diagnostics, the Company 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.

AlloMap is a gene expression test that helps clinicians monitor and identify heart transplant recipients with stable graft function who have a low probability of moderate to severe acute cellular rejection. Since 2008, the Company has sought to expand the adoption and utilization of its AlloMap solution through ongoing studies to substantiate the clinical utility and actionability of AlloMap, secure positive reimbursement decisions for AlloMap from large private and public payers, develop and enhance its relationships with key members of the transplant community, including opinion leaders at major transplant centers, and explore opportunities and technologies for the development of additional solutions for post-transplant surveillance. The Company believes the use of AlloMap, in conjunction with other clinical indicators, can help healthcare providers and their patients better manage long-term care following a heart transplant. In particular, the Company believes AlloMap can improve patient care by helping healthcare providers avoid the use of unnecessary, invasive surveillance biopsies and determine the appropriate dosage levels of immunosuppressants. AlloMap has received 510(k) clearance from the U.S. Food and Drug Administration (the “FDA”) for marketing and sale as a test to aid in the identification of recipients with a low probability of moderate or severe acute cellular rejection. A 510(k) submission is a premarketing submission made to the FDA. Clearance may be granted by the FDA if it finds the device or test provides satisfactory evidence pertaining to the claimed intended uses and indications for the device or test.

On October 9, 2017, the Company commercially launched AlloSure, its proprietary next-generation sequencing-based test to measure dd-cfDNA after transplantation. The Company believes the use of AlloSure, in conjunction with other clinical indicators, can help healthcare providers and their patients better manage long-term care following a kidney transplant. In particular, the Company believes AlloSure can improve patient care by helping healthcare providers to reduce the use of invasive biopsies and determine the appropriate dosage levels of immunosuppressants.

The Company also develops, manufactures, markets and sells products that increase the chance of successful transplants by facilitating a better match between a donor and a recipient of stem cells and organs. Olerup SSP® is used to type Human Leukocyte Antigen, or HLA alleles, based on the sequence specific primer, or SSP technology. Olerup SBT^TM is a complete product range for sequence-based typing, of HLA alleles. Olerup QTYPE® enables speed and precision in HLA typing at a low to intermediate resolution for samples that require a fast turn-around-time and uses real-time polymerase chain reaction, or PCR methodology. QTYPE received CE mark certification on April 10, 2018.

On May 4, 2018, the Company entered into a License and Commercialization Agreement with Illumina, Inc. (“Illumina”), which provides the Company with worldwide distribution, development and commercialization rights to Illumina’s next generation sequencing (“NGS”) product line for use in transplantation diagnostic testing. See Note 17 for further details.

The Company’s headquarters are in Brisbane, California; primary operations are in Brisbane, U.S. and Stockholm, Sweden; and the Company operates in two reportable segments.

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 $274.1 million at March 31, 2018. As of March 31, 2018, the Company had cash and cash equivalents of $18.7 million, and $10.2 million of debt outstanding under its debt obligations, of which $0.5 million is current.

On April 17, 2018, the Company entered into a new credit agreement with Perceptive Credit Holdings II, LP (“Perceptive”) for an initial term loan of $15.0 million and repaid the outstanding indebtedness of the promissory notes issued by Allenex AB (“Allenex”) to FastPartner AB and Mohammed Al Moudi and the term loan and credit facility with Danske Bank A/S (“Danske”). A second tranche of $10.0 million will be available at the Company’s option subject to the satisfaction of customary conditions. Refer to Note 17 for additional details.

The Company may require additional financing in the future to fund working capital and pay its obligations as they come due. Additional financing might include one or more offerings and one or more of a combination of equity securities, debt arrangements or collaborations. However, 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 that the net proceeds from the Perceptive refinancing, as well as its existing cash balance and expected revenues, will be sufficient to meet its anticipated cash requirements for at least the next 12 months.