Ecovyst, Inc. Annual report pursuant to Section 13 and 15(d)

Restructuring and Other Related Costs - Components of Restructuring and Other Related Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and other related costs	$ 2,692	$ 6,208	$ 8,490
Other related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and other related costs	2,692	5,323	2,949
Eco Services Restructuring Plan \| Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring and other related costs	0	0	830
Performance Materials Plant Closure \| Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring and other related costs	$ 0	$ 885	$ 4,711