XML 96 R1.htm IDEA: XBRL DOCUMENT v3.3.0.814
Document And Entity Information - USD ($)
$ in Billions
 12 Months Ended
Oct. 02, 2015
Nov. 20, 2015
Mar. 27, 2015
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Oct. 02, 2015    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Trading Symbol jec    
Entity Registrant Name JACOBS ENGINEERING GROUP INC /DE/    
Entity Central Index Key 0000052988    
Current Fiscal Year End Date --10-02    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   122,557,955  
Entity Public Float     $ 5.6
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Well-known Seasoned Issuer Yes