Document And Entity Information - USD ($)
12 Months Ended
Sep. 30, 2019
Nov. 22, 2019
Mar. 29, 2019
Document And Entity Information      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Sep. 30, 2019    
Document Transition Report false    
Entity File Number 1-10596    
Entity Registrant Name ESCO Technologies Inc.    
Entity Incorporation, State or Country Code MO    
Entity Tax Identification Number 43-1554045    
Entity Address, Address Line One 9900A Clayton Road    
Entity Address, City or Town St. Louis    
Entity Address, State or Province MO    
Entity Address, Postal Zip Code 63124-1186    
City Area Code 314    
Local Phone Number 213-7200    
Title of 12(b) Security Common Stock, par value $0.01 per share    
Trading Symbol ESE    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 1,698,000,000
Entity Common Stock, Shares Outstanding   25,981,313  
Entity Central Index Key 0000866706    
Current Fiscal Year End Date --09-30    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Voluntary Filers No