Amount of annual license maintenance fees paid under an license agreement.

No definition available.

Name:	kala_AnnualLicenseMaintenanceFee
Namespace Prefix:	kala_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Annual license maintenance fees owed to Stanford for specific regulatory milestones.

+ References

No definition available.

+ Details

Name:	kala_AnnualLicenseMaintenanceFeesUponAchievementOfSpecificMilestones
Namespace Prefix:	kala_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of contingent milestone consideration payable in cash in connection with asset acquisition.

+ References

No definition available.

+ Details

Name:	kala_AssetAcquisitionContingentMilestoneConsiderationCashPaid
Namespace Prefix:	kala_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of acquirer's equity interest issued and issuable as part of contingent milestone consideration transferred in asset acquisition.

+ References

No definition available.

+ Details

Name:	kala_AssetAcquisitionContingentMilestoneConsiderationEquityInterestIssuedOrIssuable
Namespace Prefix:	kala_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of shares of acquirer's equity interest issued and issuable as part of contingent milestone consideration transferred in asset acquisition.

+ References

No definition available.

+ Details

Name:	kala_AssetAcquisitionContingentMilestoneConsiderationNumberOfEquityInterestIssuedOrIssuable
Namespace Prefix:	kala_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of contingent milestone consideration in connection with asset acquisition.

+ References

No definition available.

+ Details

Name:	kala_AssetAcquisitionContingentMilestoneConsiderationPayable
Namespace Prefix:	kala_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of potential maximum payout for contingent consideration contingent upon the achievement of specified development, regulatory and sales-based milestones related to specified product.

+ References

No definition available.

+ Details

Name:	kala_PotentialMaximumPayoutForContingentConsideration
Namespace Prefix:	kala_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Potential payout for contingent consideration upon achievement of specified development , regulatory and commercial milestones.

+ References

No definition available.

+ Details

Name:	kala_PotentialPayoutForContingentConsiderationUponAchievementOfSpecifiedDevelopmentRegulatoryAndCommercialMilestones
Namespace Prefix:	kala_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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

- Details

Name:	srt_StatementScenarioAxis=kala_ScenarioAchievementOfSpecifiedDevelopmentAndRegulatoryMilestonesRelatingToKPI012ProductMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=kala_ScenarioAchievementOfSalesBasedMilestoneRelatingToKpi012ProductMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetAcquisitionAxis=kala_CombangioIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=kala_FirstPatientDosedWithAnyProductInPhase2ClinicalTrialDosingMilestoneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

COMMITMENTS AND CONTINGENCIES - Contingencies Related to Stanford and Merger Agreement (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended	6 Months Ended
	Mar. 31, 2023	Feb. 28, 2023	Jun. 30, 2026	Jun. 30, 2026	Jan. 31, 2024	Nov. 15, 2021
Other Commitments
Annual license maintenance fee			$ 0	$ 0
Achievement of specified development and regulatory milestones relating to KPI-012 product \| Maximum
Other Commitments
Annual license maintenance fees owed to Stanford for specific regulatory milestones			1,075	1,075
Achievement of sales based milestone relating to KPI-012 product
Other Commitments
Annual license maintenance fees owed to Stanford for specific regulatory milestones			$ 1,100	$ 1,100
Combangio, Inc.
Other Commitments
Contingent upon specified development, regulatory and commercialization milestones						$ 40,000
Combangio, Inc. \| Achievement of sales based milestone relating to KPI-012 product
Other Commitments
Potential maximum payout for contingent consideration						$ 65,000
Combangio, Inc. \| First patient dosed with any product in phase 2 clinical trial, dosing milestone
Other Commitments
Contingent milestone consideration paid		$ 2,500
Contingent milestone consideration paid in shares value		$ 2,354
Contingent milestone consideration paid in shares	2,100
Contingent milestone consideration					$ 146