v2.4.1.9

Debt - Summary of Aggregate Annual Payments Due (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Less: current portion	$ (5,961)us-gaap_LongTermDebtCurrent	$ (4,461)us-gaap_LongTermDebtCurrent
Long-term portion	5,451us-gaap_LongTermDebtNoncurrent	10,914us-gaap_LongTermDebtNoncurrent
2012 Loan [Member]
Debt Instrument [Line Items]
Year ending December 31, 2015	6,802cdna_LongTermDebtMaturitiesRepaymentsInNextTwelveMonths / us-gaap_LongtermDebtTypeAxis = cdna_TwoThousandTwelveTermLoanMember
Year ending December 31, 2016	5,809cdna_LongTermDebtMaturitiesRepaymentsInYearTwo / us-gaap_LongtermDebtTypeAxis = cdna_TwoThousandTwelveTermLoanMember
Total remaining debt payments	12,611cdna_LongTermDebtMaturitiesRepayments / us-gaap_LongtermDebtTypeAxis = cdna_TwoThousandTwelveTermLoanMember
Less: amounts representing interest	(2,204)cdna_LongTermDebtMaturitiesRepaymentsOfInterest / us-gaap_LongtermDebtTypeAxis = cdna_TwoThousandTwelveTermLoanMember
Equals: debt principal balance as of December 31, 2014	10,407cdna_LongTermDebtMaturitiesRepaymentsOfPrincipal / us-gaap_LongtermDebtTypeAxis = cdna_TwoThousandTwelveTermLoanMember
Plus: unamortized premium, net	899us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet / us-gaap_LongtermDebtTypeAxis = cdna_TwoThousandTwelveTermLoanMember
Equals: debt balance as of December 31, 2014 including accrued interest, net of unaccreted discount	11,306us-gaap_LongTermDebt / us-gaap_LongtermDebtTypeAxis = cdna_TwoThousandTwelveTermLoanMember
Less: current portion	(5,961)us-gaap_LongTermDebtCurrent / us-gaap_LongtermDebtTypeAxis = cdna_TwoThousandTwelveTermLoanMember
Long-term portion	5,345us-gaap_LongTermDebtNoncurrent / us-gaap_LongtermDebtTypeAxis = cdna_TwoThousandTwelveTermLoanMember
Equals: debt balance as of December 31, 2014 including accrued interest, net of unaccreted discount	$ 11,306us-gaap_LongTermDebt / us-gaap_LongtermDebtTypeAxis = cdna_TwoThousandTwelveTermLoanMember

X

- Definition

Long term debt maturities repayments.

+ References

No definition available.

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X

- Definition

Long term debt maturities repayments in next twelve months.

+ References

No definition available.

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X

- Definition

Long term debt maturities repayments in year two.

+ References

No definition available.

+ Details

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X

- Definition

Long Term Debt Maturities Repayments Of Interest

+ References

No definition available.

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- Definition

Long Term Debt Maturities Repayments Of Principal

+ References

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X

- Definition

The amount of debt discount (net of debt premium) that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399



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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

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- Definition

Amount of long-term debt, after unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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