Ecovyst, Inc. Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments - Effect on Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Amount of gain (loss) recognized in OCI on derivatives
Amount of gain (loss) recognized in OCI on derivatives	$ (1,812)	$ 580	$ (3,814)	$ 3,485
Amount of gain (loss) reclassified from AOCI into income
Amount of gain (loss) reclassified from AOCI into income	(256)	(157)	(188)	(164)
Interest rate caps
Amount of gain (loss) recognized in OCI on derivatives
Amount of gain (loss) recognized in OCI on derivatives	(675)	451	(3,048)	3,303
Interest rate caps \| Interest expense
Amount of gain (loss) reclassified from AOCI into income
Amount of gain (loss) reclassified from AOCI into income	(169)	(58)	(292)	(93)
Natural gas swaps
Amount of gain (loss) recognized in OCI on derivatives
Amount of gain (loss) recognized in OCI on derivatives	(1,137)	129	(766)	182
Natural gas swaps \| Cost of goods sold
Amount of gain (loss) reclassified from AOCI into income
Amount of gain (loss) reclassified from AOCI into income	$ (87)	$ (99)	$ 104	$ (71)