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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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Net number of share options (or share units) granted during the period.

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Number of options outstanding, including both vested and non-vested options.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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Stock-Based Compensation - Additional Information (Detail) - USD ($)				1 Months Ended		12 Months Ended
	Jun. 01, 2017	Jan. 31, 2017	Apr. 29, 2016	May 31, 2017	May 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued						54,355,535	53,672,861
Common stock reserved for issuance						18,000,000
Vesting period						3 years
Number of stock options outstanding						0	0
Tax benefit realized from stock-based plans							$ 1,254,000	$ 837,000
Capitalization of share based payment costs						$ 471,000	$ 471,000
Options granted						0	0	0
Total intrinsic value of options exercised								$ 494,000
Restricted stock units, weighted average grant date fair value						$ 13.14	$ 8.52	$ 8.16
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options outstanding						0	0
Cash received from employees as a result of employee stock option exercises								$ 592,000
Tax benefit realized from stock-based plans								$ 21,000
Number of stock options exercisable						0	0
Stock Incentive Plan 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance						14,548,013
Shares available for future grant						18,000,000
Percentage of exercise price fair value option grant in period						100.00%
Number of shares returned for each common stock						2.4
Stock Incentive Plans 2001 and After [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of exercise price fair value option grant in period						100.00%
Stock options granted to employees under plans prior to 2001, vested per quarter thereafter						6.25%
Stock options expired						10 years
Stock Incentive Plans 2001 and After [Member] \| Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted to employees under plans prior to 2001, vested after one year						25.00%
1997 Director Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award vesting period description						Options granted to directors generally vested at the earliest of (1) one day prior to the next annual meeting, (2) 13 months from the date of grant, or (3) the effective date of an acquisition.
Number of stock options outstanding						0	0
1997 Director Plan [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period						1 day
1997 Director Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period						13 months
2014 ESPP Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance						2,500,000
Percentage of payroll deduction to compensation						Up to 10%
Percentage of Common Stock through payroll deductions						10.00%
Amount of payroll deduction	$ 22,500,000					$ 21,250,000
Amount of payroll deduction increased						$ 22,500,000
Percentage of closing price of the Common Stock		90.00%				85.00%
Common stock, shares issued						105,506	139,079	140,531
Common stock reserved for issuance						2,032,403
2014 ESPP Plan [Member] \| Offer Terminate [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of closing price of the Common Stock		90.00%				85.00%
2014 ESPP Plan [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, exercise price						$ 46.37	$ 31.40	$ 30.74
2014 ESPP Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, exercise price						$ 74.12	$ 35.16	$ 31.34
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued as per merger agreement						1,260,525
Number of RSUs outstanding						12,134	17,462
Dividend reinvestment						122	187
Restricted stock units, weighted average grant date fair value						$ 67.69
Total intrinsic value of options, stock appreciation rights exercised and fair value of RSUs vested						$ 60,302,000	$ 18,844,000	$ 12,868,000
Total compensation expense related to restricted stock unites and stock appreciation rights						$ 20,314,000
Estimated weighted average amortization period						11 months 4 days
Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted to employees under plans prior to 2001, vested after one year						33.00%	33.00%	33.00%
Restricted Stock Units (RSUs) [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period						1 day
Restricted Stock Units (RSUs) [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period						13 months
Restricted Stock Units (RSUs) [Member] \| Newport Deferred Compensation [Member] \| Outside Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Newport RSUs converted to MKS RSUs at Merger date						36,599
Newport RSUs converted to MKS RSUs at Merger date and released				5,515	19,137
RSUs Granted to Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award vesting period description						Employees who are at least 60 years old and have a minimum of 10 Years of Service (as defined in the applicable RSU agreement) are expensed immediately.
Minimum years of service for RSU						10 years
RSUs Granted to Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award vesting period description						Earliest of (1) one day prior to the next annual meeting, (2) 13 months from date of grant, or (3) the effective date of a change in control of the Company.
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of options, stock appreciation rights exercised and fair value of RSUs vested						$ 60,302,000	$ 18,844,000	$ 12,868,000
Total compensation expense related to restricted stock unites and stock appreciation rights						$ 20,314,000
Estimated weighted average amortization period						11 months 4 days
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of options, stock appreciation rights exercised and fair value of RSUs vested						$ 60,302,000	$ 18,844,000	$ 12,868,000
Newport [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued as per merger agreement			360,674
Newport [Member] \| Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued as per merger agreement			899,851