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Stock-Based Compensation - Additional Information (Detail) $ in Millions | 9 Months Ended
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Sep. 30, 2020 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Common stock reserved for issuance | 18,000,000
Total compensation expense related to unvested stock-based awards granted to employees, officers and directors | $ | $ 37.7
Restricted Stock Units (RSUs) [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Shares issued as per merger agreement | 749,000
Restricted Stock Units (RSUs) [Member] | ESI Plan member [Member] | Outside Directors [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Newport RSUs converted to MKS RSUs at Merger date | 326,000
Newport Corporation | Restricted Stock Units (RSUs) [Member] | ESI Plan member [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Shares issued as per merger agreement | 736,000
Newport Corporation | Stock Appreciation Rights (SARs) [Member] | ESI Plan member [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Shares issued as per merger agreement | 13,000

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