Description of Plan (Details) - EBP 003 - USD ($)	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
EBP, Description of Plan [Line Items]
Transfers in	$ 668,218	$ 0
Transfers in, participant account balance	654,214
Transfers in, participant loan balance	$ 14,004
Pretax, non-highly compensated employee, maximum annual compensation to total compensation, percentage	50.00%
Pretax, highly compensated employee, maximum annual compensation to total compensation, percentage	20.00%
Matching percentage	50.00%
Participant compensation matched, percentage	6.00%
Employer contribution, annual contribution	$ 5,058,089	4,602,923
Forfeited nonvested account, decrease from employer	288,854	309,850
Forfeited, unused	285,356	$ 186,046
Minimum borrowing, amount	1,000
Maximum borrowing, amount	$ 50,000
Maximum borrowing, to total account, percentage	50.00%
Participant loan, interest rate	4.25%	9.50%
General loan, borrowing term	5 years
Primary residence, borrowing term	15 years
Investment, Identifier [Axis]: Ecovyst Stock Fund
EBP, Description of Plan [Line Items]
Maximum annual compensation to total compensation, percentage	15.00%
EBP, Employer Matching Contribution
EBP, Description of Plan [Line Items]
Vesting period	3 years
EBP, Employer Matching Contribution \| EBP, Employer Contribution, Tranche One
EBP, Description of Plan [Line Items]
Vesting percentage	33.33%
EBP, Employer Matching Contribution \| EBP, Employer Contribution, Tranche Two
EBP, Description of Plan [Line Items]
Vesting percentage	33.33%
EBP, Employer Matching Contribution \| EBP, Employer Contribution, Tranche Three
EBP, Description of Plan [Line Items]
Vesting percentage	33.33%
EBP, Employer Annual Contribution
EBP, Description of Plan [Line Items]
Vesting period	3 years
Vesting percentage	100.00%
Minimum
EBP, Description of Plan [Line Items]
Employer contribution, annual contribution, percentage	4.00%
Participant loan, interest rate	425.00%
Maximum
EBP, Description of Plan [Line Items]
Employer contribution, annual contribution, percentage	8.00%
Participant loan, interest rate	950.00%

EBP, Change in Net Asset Available for Benefit, Transfer to (from) Plan, Participant Account

No definition available.

Name:	ecvt_EBPChangeInNetAssetAvailableForBenefitTransferToFromPlanParticipantAccount
Namespace Prefix:	ecvt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

EBP, Change in Net Asset Available for Benefit, Transfer to (from) Plan, Participant Loan

+ References

No definition available.

+ Details

Name:	ecvt_EBPChangeInNetAssetAvailableForBenefitTransferToFromPlanParticipantLoan
Namespace Prefix:	ecvt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

EBP, Employer Contribution, Annual Contribution

+ References

No definition available.

+ Details

Name:	ecvt_EBPEmployerContributionAnnualContribution
Namespace Prefix:	ecvt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

EBP, Employer Contribution, Annual Contribution, Percentage

+ References

No definition available.

+ Details

Name:	ecvt_EBPEmployerContributionAnnualContributionPercentage
Namespace Prefix:	ecvt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Employer Contribution Vesting Percentage

+ References

No definition available.

+ Details

Name:	ecvt_EBPEmployerContributionVestingPercentage
Namespace Prefix:	ecvt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Employer Contribution Vesting Service Period

+ References

No definition available.

+ Details

Name:	ecvt_EBPEmployerContributionVestingServicePeriod
Namespace Prefix:	ecvt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Note Receivable From Participant, Account, Primary Residence, Maximum Borrowing Term

+ References

No definition available.

+ Details

Name:	ecvt_EBPNoteReceivableFromParticipantAccountPrimaryResidenceMaximumBorrowingTerm
Namespace Prefix:	ecvt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Note Receivable From Participant, General Loan, Maximum Borrowing Term

+ References

No definition available.

+ Details

Name:	ecvt_EBPNoteReceivableFromParticipantGeneralLoanMaximumBorrowingTerm
Namespace Prefix:	ecvt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Participant Contribution, Maximum Contribution to Eligible Compensation, Percentage

+ References

No definition available.

+ Details

Name:	ecvt_EBPParticipantContributionMaximumContributionToEligibleCompensationPercentage
Namespace Prefix:	ecvt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Participant Contribution, Pretax, Maximum Contribution For Highly Compensated Employees To Compensation, Percentage

+ References

No definition available.

+ Details

Name:	ecvt_EBPParticipantContributionPretaxMaximumContributionForHighlyCompensatedEmployeesToCompensationPercentage
Namespace Prefix:	ecvt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Participant Contribution, Pretax, Maximum Contribution For Non-Highly Compensated Employees To Compensation, Percentage

+ References

No definition available.

+ Details

Name:	ecvt_EBPParticipantContributionPretaxMaximumContributionForNonHighlyCompensatedEmployeesToCompensationPercentage
Namespace Prefix:	ecvt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of net asset available for benefit transferred to (from) employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) from (to) external plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule III))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 45
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477063/962-205-45-8

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employer matching contribution on eligible participant contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanEmployerContributionMatchingPercentage
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of participant compensation eligible for employer matching contribution for participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanEmployerContributionParticipantCompensationMatchedPercentage
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of plan asset, in forfeited nonvested account, no longer allocated to participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccount
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of decrease in forfeited nonvested account of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) from employer contribution.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (j)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-04(5)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccountDecreaseForEmployerContribution
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow.

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingAmount
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow to total participant account balance.

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMaximumBorrowingToTotalAccountPercentage
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of minimum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow.

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipantAccountMinimumBorrowingAmount
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Interest rate on participant loan in schedule of asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 10
-Paragraph b
-Subparagraph (1)(i)(D)
-Publisher DOL-EBSA

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule I))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=ecvt_EBP003Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentIdentifierAxis=Ecovyst Stock Fund
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ecvt_EBPEmployerContributionTypeAxis=ecvt_EBPEmployerMatchingContributionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ecvt_EBPEmployerContributionVestingAxis=ecvt_EBPEmployerContributionTrancheOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ecvt_EBPEmployerContributionVestingAxis=ecvt_EBPEmployerContributionTrancheTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ecvt_EBPEmployerContributionVestingAxis=ecvt_EBPEmployerContributionTrancheThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ecvt_EBPEmployerContributionTypeAxis=ecvt_EBPEmployerAnnualContributionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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