The amount of milestone payment due upon approval of rucaparib by a government agency for a particular treatment.

No definition available.

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Data Type:	xbrli:monetaryItemType
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- Definition

Aggregate maximum possible milestone payments to be made on attaining sales targets.

+ References

No definition available.

+ Details

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Namespace Prefix:	clvs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the amount of deferred milestone payment agreed to be paid within the specified period.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Maximum potential development regulatory milestone payments to be made in the future if regulatory and other milestones are met.

+ References

No definition available.

+ Details

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- Definition

The amount of annual sales target above which the majority of the sales milestone payments must be made.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

Amount of cash payments incurred to license the use and development of a drug product from the licensor. The upfront payments are expensed to acquired in process research and development if it is determined that the in-licensed product does not have an alternative future use at the time the in-license agreement is executed.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of acquired in process research and development milestones paid to Pfizer prior to FDA approval of Rucaparib.

+ References

No definition available.

+ Details

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Namespace Prefix:	clvs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of additional undisclosed targets.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum number of months after the FDA approval for Rubraca (rucaparib) tablets upon which payment will be made to counterparty.

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
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- Definition

Percentage of consideration payable on sublicense agreements.

+ References

No definition available.

+ Details

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Namespace Prefix:	clvs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of royalty on net sales of licensed products.

+ References

No definition available.

+ Details

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Namespace Prefix:	clvs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Milestone payments due under licensing agreements.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Milestone payments under in-licensing agreements.

+ References

No definition available.

+ Details

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Namespace Prefix:	clvs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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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- Definition

The amount of the write-off for research and development assets that were acquired in a transaction other than a business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 730
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6420194&loc=d3e21568-108373

+ Details

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

- Details

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Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
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- Details

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Balance Type:
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- Details

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- Details

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- Details

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- Details

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License Agreements (Details) $ in Thousands				1 Months Ended										3 Months Ended	6 Months Ended	12 Months Ended
License Agreements (Details) $ in Thousands	Dec. 19, 2016 USD ($)	Aug. 30, 2016	Nov. 19, 2013 USD ($)	Jun. 30, 2020 USD ($)	May 31, 2020 USD ($)	Feb. 29, 2020 item	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Feb. 28, 2019 USD ($)	Jun. 30, 2018 USD ($)	Apr. 30, 2018 USD ($)	Jun. 30, 2011 USD ($)	Oct. 31, 2008	Mar. 31, 2017 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Rucaparib
License Agreements
Milestone payments								$ 750
Rucaparib \| EMA [Member]
License Agreements
Milestone payment obligation									$ 15,000	$ 20,000
Rucaparib \| First approval of NDA by FDA
License Agreements
Milestone payment obligation											$ 15,000
Rucaparib \| Third approval of Rubraca as monotherapy treatment
License Agreements
Milestone payments				$ 8,000
Milestone payment obligation					$ 8,000
3B Pharmaceuticals
License Agreements
Percentage of Non-Royalty Consideration Payable on Sublicense Agreements															34.00%
License Agreements Licensor Pfizer \| Rucaparib
License Agreements
Milestone payments										$ 23,000				$ 750
Milestone payment obligation	$ 750
Milestone payment incurred as a result of government approval	20,000
Deferred milestone payment	$ 23,000
Maximum number of months after FDA approval	18 months	18 months
License Agreements Licensor Pfizer \| Rucaparib \| Minimum
License Agreements
Annual sales target for sales milestone payments															$ 250,000
License Agreements Licensor Pfizer \| Rucaparib \| Maximum
License Agreements
Maximum potential future development, regulatory milestone payments															8,000
Additional maximum payments payable on attaining the sales target				$ 170,000											$ 170,000
License Agreement Terms \| 3B Pharmaceuticals
License Agreements
Acquired in-process research and development							$ 9,400
Number of additional undisclosed targets \| item						3
Research and development expense																$ 2,100
Percentage Of Royalty On Net Sales															6.00%
License Agreement Terms \| License Agreements Licensor Pfizer \| Rucaparib
License Agreements
Upfront payment												$ 7,000
Milestones paid to Pfizer prior to FDA approval												$ 1,400
License Agreement Terms \| Advenchen Laboratories LLC \| License Agreements Lucitanib
License Agreements
Milestone payment obligation			$ 65,000
Percentage of Non-Royalty Consideration Payable on Sublicense Agreements													25.00%