XML 48 R1.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Cover Page - USD ($)
 12 Months Ended
Dec. 31, 2019
Feb. 19, 2020
Jun. 28, 2019
Cover [Abstract]      
Amendment Flag false    
Document Type 10-K    
Document Annual Report true    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Document Transition Report false    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Document Period End Date Dec. 31, 2019    
Entity Interactive Data Current Yes    
Entity Current Reporting Status Yes    
Entity Registrant Name MKS INSTRUMENTS INC    
Entity Central Index Key 0001049502    
Trading Symbol MKSI    
Entity Filer Category Large Accelerated Filer    
Entity Shell Company false    
Entity Emerging Growth Company false    
Entity Small Business false    
Entity Common Stock, Shares Outstanding   54,866,512  
Entity Public Float     $ 4,224,355,318
Entity File Number 0-23621    
Entity Tax Identification Number 04-2277512    
Entity Address, Address Line One 2 Tech Drive, Suite 201    
Entity Address, City or Town Andover    
Entity Address, State or Province MA    
Entity Address, Postal Zip Code 01810    
Entity Incorporation, State or Country Code MA    
City Area Code 978    
Local Phone Number 645-5500    
Security Exchange Name NASDAQ    
Title of 12(b) Security Common Stock