Derivative financial instruments - Schedule of Aggregate Notional Principal Amounts of Outstanding Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Derivative [Line Items]
Balance sheet exposure asset (liability)	$ (111,893)	$ (89,569)
United States Dollars (sell) Indian Rupees (buy)
Derivative [Line Items]
Notional principal amounts	2,278,467	2,771,310
Balance sheet exposure asset (liability)	(108,460)	(72,843)
United States Dollars (sell) Mexican Peso (buy)
Derivative [Line Items]
Notional principal amounts	50,400	71,400
Balance sheet exposure asset (liability)	4,215	2,201
United States Dollars (sell) Philippines Peso (buy)
Derivative [Line Items]
Notional principal amounts	187,100	234,000
Balance sheet exposure asset (liability)	(8,979)	(5,739)
Euro (sell) United States Dollars (buy)
Derivative [Line Items]
Notional principal amounts	385,648	446,846
Balance sheet exposure asset (liability)	4,705	(9,636)
Euro (sell) Romanian Leu (buy)
Derivative [Line Items]
Notional principal amounts	30,837	63,353
Balance sheet exposure asset (liability)	(310)	143
Japanese Yen (sell) Chinese Renminbi (buy)
Derivative [Line Items]
Notional principal amounts	62,939	67,617
Balance sheet exposure asset (liability)	7,118	3,746
United States Dollars (sell) Chinese Renminbi (buy)
Derivative [Line Items]
Notional principal amounts	61,800	82,800
Balance sheet exposure asset (liability)	1,963	144
Pound Sterling (sell) United States Dollars (buy)
Derivative [Line Items]
Notional principal amounts	68,167	92,322
Balance sheet exposure asset (liability)	492	(279)
United States Dollars (sell) Hungarian Forint (buy)
Derivative [Line Items]
Notional principal amounts	20,000	33,000
Balance sheet exposure asset (liability)	2,279	2,524
Australian Dollars (sell) Indian Rupees (buy)
Derivative [Line Items]
Notional principal amounts	171,591	189,797
Balance sheet exposure asset (liability)	(15,003)	(8,204)
United States Dollars (sell) Polish Zloty (buy)
Derivative [Line Items]
Notional principal amounts	28,500	42,000
Balance sheet exposure asset (liability)	(69)	1,884
Japanese Yen (sell) United States Dollars (buy)
Derivative [Line Items]
Notional principal amounts	0	7,000
Balance sheet exposure asset (liability)	0	238
United States Dollars (sell) Israeli Shekel (buy)
Derivative [Line Items]
Notional principal amounts	30,000	30,000
Balance sheet exposure asset (liability)	1,467	1,025
South African Rand (sell) United States Dollars (buy)
Derivative [Line Items]
Notional principal amounts	15,000	18,000
Balance sheet exposure asset (liability)	(1,346)	(1,186)
United States Dollars (sell) Brazilian Real (buy)
Derivative [Line Items]
Notional principal amounts	4,000	4,000
Balance sheet exposure asset (liability)	244	(46)
United States Dollars (sell) Costa Rica Colon (buy)
Derivative [Line Items]
Notional principal amounts	27,500	44,400
Balance sheet exposure asset (liability)	2,758	773
United States Dollars (sell) Canadian Dollar (buy)
Derivative [Line Items]
Notional principal amounts	9,000	9,000
Balance sheet exposure asset (liability)	(167)	193
United States Dollars (sell) Malaysian Ringgit (buy)
Derivative [Line Items]
Notional principal amounts	21,500	21,000
Balance sheet exposure asset (liability)	(64)	486
United States Dollars (sell) Singapore Dollar (buy)
Derivative [Line Items]
Notional principal amounts	75,000	0
Balance sheet exposure asset (liability)	(972)	0
Interest rate swaps (floating to fixed)
Derivative [Line Items]
Notional principal amounts	215,625	221,875
Balance sheet exposure asset (liability)	$ (1,764)	$ (4,993)