Beneficial ownership acquired, percentage

No definition available.

Name:	kzr_BeneficialOwnershipAcquiredPercentage
Namespace Prefix:	kzr_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Purchase price of shares upon rights exercise.

+ References

No definition available.

+ Details

Name:	kzr_PurchasePriceOfSharesUponRightsExercise
Namespace Prefix:	kzr_
Data Type:	dtr-types:perShareItemType
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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-3

+ Details

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

- Definition

Number of common shares issuable upon conversion for each share of preferred stock to be converted.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

+ Details

Name:	us-gaap_PreferredStockConvertibleConversionRatio
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares of preferred stock issued as dividends during the period. Excludes stock splits.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480100/505-10-S45-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480657/210-10-S50-11

+ Details

Name:	us-gaap_PreferredStockDividendsShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480100/505-10-S45-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477657/942-210-S45-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478478/942-210-S50-1

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480657/210-10-S50-11

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

+ Details

Name:	us-gaap_PreferredStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_StatementClassOfStockAxis=kzr_SeriesAJuniorParticipatingPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=kzr_StockholderRightsPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=kzr_PassiveInstitutionalInvestorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stockholders' Equity (Details)	Oct. 17, 2024 $ / shares shares	Mar. 31, 2026 $ / shares	Dec. 31, 2025 $ / shares
Class Of Warrant Or Right [Line Items]
Purchase price (in dollars per share)	$ 71.60
Preferred stock, par value (in dollars per share)		$ 0.001	$ 0.001
Series A Junior Participating Preferred Stock
Class Of Warrant Or Right [Line Items]
Preferred stock, convertible, conversion ratio	0.01
Preferred stock, par value (in dollars per share)	$ 0.001
Stockholder Rights Plan
Class Of Warrant Or Right [Line Items]
Preferred dividend (in shares) \| shares	1
Beneficial ownership acquired (as a percent)	10.00%
Passive Institutional Investor
Class Of Warrant Or Right [Line Items]
Beneficial ownership acquired (as a percent)	15.00%