Represents the number of opponents in legal case.

No definition available.

Name:	clvs_NumberOfOpponents
Namespace Prefix:	clvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of patents of which oppositions filed regarding salt and polymorph patents.

+ References

No definition available.

+ Details

Name:	clvs_NumberOfOppositionsFiledSaltAndPolymorphPatents
Namespace Prefix:	clvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of putative shareholders of the Company, the "Derivative Plaintiffs", that filed shareholder derivative complaints against certain directors and officers of the Company in the Court of Chancery of State of Delaware.

+ References

No definition available.

+ Details

Name:	clvs_NumberOfPutativeShareholdersFilingComplaint
Namespace Prefix:	clvs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of years for possible additional regulatory exclusivity in Europe regarding patents.

+ References

No definition available.

+ Details

Name:	clvs_NumberOfYearsPossibleAdditionalRegulatoryExclusivity
Namespace Prefix:	clvs_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the regulatory exclusivity in Europe in number of years relating to patents.

+ References

No definition available.

+ Details

Name:	clvs_NumberOfYearsRegulatoryExclusivity
Namespace Prefix:	clvs_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Minimum amount to be expended to satisfy the terms of arrangements in which the entity has agreed to expend funds to procure goods or services, excluding long-term purchase commitments or unconditional purchase obligations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(17))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(19))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(25))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

Commitments and Contingencies (Details) $ in Millions			1 Months Ended	6 Months Ended
Commitments and Contingencies (Details) $ in Millions	Nov. 10, 2019 plaintiff	Jun. 20, 2017 plaintiff patent	Mar. 31, 2017 shareholder	Jun. 30, 2020 USD ($)
Commitments and Contingencies
Purchase commitments \| $				$ 74.5
Number of putative shareholders \| shareholder			2
Number of patents in salt and polymorph patent family \| patent		2
Number of opponents \| plaintiff	1	2
Number of years regulatory exclusivity in Europe				10 years
Number of years possible additional regulatory exclusivity				1 year