v3.26.1
Long-term debt - Narrative (Details) - USD ($)
 6 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Nov. 30, 2025
Jun. 30, 2024
Mar. 31, 2021
Debt Instrument [Line Items]          
Margin over LIBOR (in percentage) 1.375%        
Net debt to EBITDA leverage ratio, covenant line of credit 300.00%        
Interest coverage minimum ratio, covenant line of credit 300.00%        
Long-term debt, amount $ 1,180,257,000 $ 1,542,301,000      
Credit facility, net of unamortized debt issuance costs          
Debt Instrument [Line Items]          
Debt issuance costs, net 429,000 584,000      
Long-term debt, amount 436,821,000 449,916,000      
Principal amount of term loan $ 6,625,000        
2022 Facility | Maximum          
Debt Instrument [Line Items]          
Term SOFR adjustment (in percentage) 0.10%        
2022 Facility | Minimum          
Debt Instrument [Line Items]          
Term SOFR adjustment (in percentage) 0.00%        
2022 Facility | Line of Credit          
Debt Instrument [Line Items]          
Debt instrument, face amount $ 650,000,000        
2022 Facility | Credit facility, net of unamortized debt issuance costs          
Debt Instrument [Line Items]          
Debt instrument, face amount $ 530,000,000        
Amended 2015 Facility          
Debt Instrument [Line Items]          
Margin over LIBOR (in percentage) 0.20%        
Credit facility, base rate (in percentage) 0.375%        
1.750% 2021 Senior Notes, net of unamortized debt issuance costs          
Debt Instrument [Line Items]          
Long-term debt, amount $ 0 349,835,000      
Interest rate on senior notes (in percentage) 1.75%        
1.750% 2021 Senior Notes, net of unamortized debt issuance costs | Genpact Luxembourg S.r.l.          
Debt Instrument [Line Items]          
Debt instrument, face amount         $ 350,000,000
Debt issuance costs, net $ 0 165,000      
Long-term debt, amount $ 0 349,835,000      
Interest rate on senior notes (in percentage)         1.75%
Total debt issuance cost         $ 3,032,000
Debt instrument redemption price (in percentage) 100.00%        
Debt repurchase price as percentage of aggregate principal value upon certain change of controls (in percentage) 101.00%        
6.000% 2024 Senior Notes, net of unamortized debt issuance costs          
Debt Instrument [Line Items]          
Long-term debt, amount $ 397,429,000 396,994,000      
Interest rate on senior notes (in percentage) 6.00%        
6.000% 2024 Senior Notes, net of unamortized debt issuance costs | Genpact Luxembourg and Genpact USA          
Debt Instrument [Line Items]          
Debt instrument, face amount       $ 400,000,000  
Debt issuance costs, net $ 2,571,000 3,005,000      
Long-term debt, amount 397,429,000 396,994,000      
Interest rate on senior notes (in percentage)       6.00%  
Total debt issuance cost       $ 4,395,000  
4.950% 2025 Senior Notes, net of unamortized debt issuance costs          
Debt Instrument [Line Items]          
Long-term debt, amount $ 346,007,000 345,556,000      
Interest rate on senior notes (in percentage) 4.95%        
4.950% 2025 Senior Notes, net of unamortized debt issuance costs | Genpact Luxembourg and Genpact USA          
Debt Instrument [Line Items]          
Debt instrument, face amount     $ 350,000    
Debt issuance costs, net $ 3,993,000 4,444,000      
Long-term debt, amount $ 346,007,000 $ 345,556,000      
Interest rate on senior notes (in percentage)     4.95%    
Total debt issuance cost     $ 4,551,000