XML 65 R55.htm IDEA: XBRL DOCUMENT
v3.21.1

Warrants - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2021 | Mar. 31, 2020
Warrants and Rights Note Disclosure [Abstract] |  |
Purchase of common stock warrants exercised (in shares) | 0 | 272,000
Proceeds from warrant exercises (less than) | $ 0 | $ 304
Number of warrants exercised on cashless basis (in shares) |  | 34,000
Shares issued (in shares) |  | 24,000

X
- Definition Number Of Warrants Exercised, Cashless Basis + References No definition available. + Details
Name: | cdna_NumberOfWarrantsExercisedCashlessBasis
Namespace Prefix: | cdna_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Purchase of common stock warrants exercised. + References No definition available. + Details
Name: | cdna_PurchaseOfCommonStockWarrantsExercised
Namespace Prefix: | cdna_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Stock Issued During Period, Shares, Cashless Warrants Exercises In Period + References No definition available. + Details
Name: | cdna_StockIssuedDuringPeriodSharesCashlessWarrantsExercisesInPeriod
Namespace Prefix: | cdna_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash inflow associated with the amount received from holders exercising their stock warrants. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromWarrantExercises
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_WarrantsAndRightsNoteDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration