v2.4.1.9

Stock Incentive Plans - Schedule of Shares Issued and Associated Expense (Detail) (USD $) | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Dec. 31, 2014 | Sep. 30, 2014 | Dec. 31, 2014 | Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract] |  |  |  |
Number of Shares Issued | 8,277us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod | 4,899us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod | 13,176us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod |
Fair Market Value per Share at Date of Issuance | $ 7.25us-gaap_SharePrice | $ 7.03us-gaap_SharePrice | $ 7.25us-gaap_SharePrice | $ 8.97us-gaap_SharePrice
Fair Value of Shares Issued | $ 60,008cdna_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriodFairValue | $ 34,440cdna_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriodFairValue | $ 94,448cdna_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriodFairValue |

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- Definition Share Based Compensation Arrangement By Share Based Payment Award Shares Issued In Period Fair Value + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
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- Definition Number of share instruments newly issued under a share-based compensation plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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Data Type: | xbrli:sharesItemType
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- Definition Price of a single share of a number of saleable stocks of a company. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant