Estimated fair value of warrant liability remeasurement income (expense)

No definition available.

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Namespace Prefix:	cdna_
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- Definition

Purchase of common stock warrants exercised.

+ References

No definition available.

+ Details

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Namespace Prefix:	cdna_
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Balance Type:	na
Period Type:	instant

- Definition

Reclassification of warrant liability to equity.

+ References

No definition available.

+ Details

Name:	cdna_ReclassificationOfWarrantLiabilityToEquity
Namespace Prefix:	cdna_
Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(2))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	instant

- Definition

The cash inflow associated with the amount received from holders exercising their stock warrants.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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- Details

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- Details

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Warrants - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended
	Jan. 01, 2018	Mar. 31, 2018	Mar. 31, 2017
Class Of Warrant Or Right [Line Items]
Estimated fair value of warrant liability remeasurement income (expense)		$ 100
Pruchase of common stock warrants exercised		23,000
Proceeds from exercise of warrants		$ 25	$ 0
Maximum [Member]
Class Of Warrant Or Right [Line Items]
Proceeds from exercise of warrants		$ 100
JGB Debt [Member]
Class Of Warrant Or Right [Line Items]
Estimated fair value of warrant liability remeasurement income (expense)			$ 400
ASU 2017-11 [Member] \| JGB Debt [Member]
Class Of Warrant Or Right [Line Items]
Warrant to purchase stock, shares	1,338,326
Reclassification of warrant liability to equity	$ 6,600