v3.26.1
Schedule H, Line 4i – Schedule of Assets (Held At End of Year) (Details) - EBP 003 - USD ($)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
EBP, Schedule of Asset Held for Investment [Line Items]    
Entity tax identification number 86-2551862  
Plan number 003  
Participant loan, interest rate 4.25% 9.50%
Notes receivable from participants $ 3,413,165  
Total $ 282,958,239  
Minimum    
EBP, Schedule of Asset Held for Investment [Line Items]    
Participant loan, interest rate 425.00%  
Maximum    
EBP, Schedule of Asset Held for Investment [Line Items]    
Participant loan, interest rate 950.00%  
Investment, Identifier [Axis]: Ecovyst Inc. | Ecovyst Stock Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value $ 323,303  
Investment, Identifier [Axis]: Fidelity Investments | Fidelity Value Fund; Retail Class    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 1,582,243  
Investment, Identifier [Axis]: PIMCO | PIMCO Total Return Fund, Administrative Class    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 1,755,622  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Cash Reserves Federal MM Fund Admiral Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 10,745,014  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Explorer Fund Investor Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 3,592,111  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Institutional Index Fund Inst'l Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 33,031,544  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard International Growth Fund Investor Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 4,178,031  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Mid-Cap Index Fund Investor Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 5,939,888  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard PRIMECAP Fund Admiral Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 32,067,409  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Small-Cap Index Fund Investor Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 4,703,783  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement 2020 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 7,443,503  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement 2025 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 15,462,144  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement 2030 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 16,827,078  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement 2035 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 15,716,107  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement 2040 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 12,015,248  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement 2045 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 12,361,330  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement 2050 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 9,340,928  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement 2055 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 6,677,518  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement 2060 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 3,292,320  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement 2065 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 869,934  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement 2070 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 32,098  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Target Retirement Income    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 5,712,944  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Total Bond Market Index Fund: Inst'l Shr    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 15,922,855  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Total International Stock Index Fund: Inst'l Shr    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 11,689,867  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Total Stock Market Index Fund: Inst'l Shr    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 13,828,623  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard U.S. Growth Fund Investor Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 8,519,787  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Wellesley Income Fund Investor Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 4,669,505  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Wellington Fund Admiral Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value 11,121,700  
Investment, Identifier [Axis]: The Vanguard Group | Vanguard Windsor II Fund Admiral Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current Value $ 10,122,637