Ecovyst, Inc. Annual report [Section 13 and 15(d), not S-K Item 405]

Financial Instruments - Cash Flow Hedge Impact on Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Interest expense	$ (49,426)	$ (44,730)	$ (37,217)
Gain (loss) on cash flow hedging relationships \| Amount of (gain) loss reclassified into Income
Derivative [Line Items]
Interest expense	$ 17,197	$ 22,731	$ (683)