v3.8.0.1
Document And Entity Information - USD ($)
12 Months Ended
Sep. 30, 2017
Nov. 06, 2017
Mar. 31, 2017
Document Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Sep. 30, 2017    
Document Fiscal Year Focus 2017    
Document Fiscal Period Focus FY    
Entity Registrant Name ESCO TECHNOLOGIES INC    
Entity Central Index Key 0000866706    
Current Fiscal Year End Date --09-30    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 1,455,041,000
Trading Symbol ESE    
Entity Common Stock, Shares Outstanding   25,835,902