v3.25.3

Financial Instruments - Narrative (Details) $ in Thousands	9 Months Ended
Financial Instruments - Narrative (Details) $ in Thousands	Sep. 30, 2025 USD ($) derivative	Nov. 30, 2025 USD ($)
Derivative
Number of instruments in effect \| derivative	3
Amount of unrealized gains expected to be transferred from AOCI	$ (2,489)
Cash flow hedging
Derivative
Notional amount	625,000
Cash flow hedging \| Interest Rate Cap One
Derivative
Notional amount	250,000
Cash flow hedging \| Interest Rate Cap Two
Derivative
Notional amount	175,000
Cash flow hedging \| Interest Rate Cap Three
Derivative
Notional amount	200,000
Cash flow hedging \| Interest Rate Cap Three \| Forecast
Derivative
Notional amount		$ 450,000
Cash flow hedging \| Interest Rate Cap Four
Derivative
Notional amount	$ 200,000

Derivative, Number of Instruments in Effect

+ References

No definition available.

+ Details

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Namespace Prefix:	ecvt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-1

+ Details

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Namespace Prefix:	us-gaap_
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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480682/815-20-25-6A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-5

+ Details

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

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 181
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-181

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=ecvt_InterestRateCapTwoMember
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- Details

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- Details

Name:	srt_StatementScenarioAxis=srt_ScenarioForecastMember
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- Details

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Namespace Prefix:
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Balance Type:
Period Type:

Ecovyst Inc. 10-Q