Document and Entity Information - shares
6 Months Ended
Jun. 30, 2019
Aug. 02, 2019
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Trading Symbol G  
Entity Registrant Name GENPACT LTD  
Entity Central Index Key 0001398659  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Common Stock, Shares Outstanding   190,501,216
Entity Current Reporting Status Yes  
Entity Shell Company false  
Entity File Number 001-33626  
Entity Tax Identification Number 980533350  
Entity Address, Address Line One Victoria Place, 5th Floor  
Entity Address, Address Line Two 31 Victoria Street  
Entity Address, City or Town Hamilton  
Entity Address, Country Bermuda  
Entity Address, Postal Zip Code HM 10  
City Area Code 441  
Local Phone Number 294-8000