DEBT - Narrative (Details) - Term Loan	Oct. 03, 2016 USD ($) payment	Mar. 31, 2018
Loan Agreement
Debt Instrument [Line Items]
Term loans, maximum borrowing capacity	$ 20,000,000.0
Period of extension if the Milestone event is achieved	6 months
Number of monthly payments of principal and interest following interest-only period \| payment	24
Variable annual rate	4.50%	5.75%
Loan Agreement \| Prime Rate
Debt Instrument [Line Items]
Prime interest rate	1.00%
Term A Loan
Debt Instrument [Line Items]
Borrowed from the Lender	$ 10,000,000.0
Term B Loan
Debt Instrument [Line Items]
Term loans, maximum borrowing capacity	$ 10,000,000.0

Debt Instrument, Extension in Interest-Only Payments Upon Achieving Milestone

No definition available.

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Namespace Prefix:	cdtx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Maximum Borrowing Capacity

+ References

No definition available.

+ Details

Name:	cdtx_DebtInstrumentMaximumBorrowingCapacity
Namespace Prefix:	cdtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Debt Instrument, Number of Payments of Principal and Interest

+ References

No definition available.

+ Details

Name:	cdtx_DebtInstrumentNumberofPaymentsofPrincipalandInterest
Namespace Prefix:	cdtx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: 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=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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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Balance Type:	na
Period Type:	duration

- Details

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- Details

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- Details

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Namespace Prefix:
Data Type:	na
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- Details

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Namespace Prefix:
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- Details

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