v3.26.1
Goodwill - Summary of Carrying Amounts of Goodwill Allocated to Cash-generating Units (Detail)
$ in Thousands, $ in Thousands
Dec. 31, 2025
TWD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
TWD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2023
TWD ($)
Dec. 31, 2022
TWD ($)
Disclosure of information for cash-generating units [line items]            
Goodwill $ 52,541,905 $ 1,674,909 $ 52,525,342 $ 1,674,381 $ 52,419,427 $ 52,313,399
Packaging segment [member]            
Disclosure of information for cash-generating units [line items]            
Goodwill 35,430,752 1,129,447 35,437,523      
Testing segment [member]            
Disclosure of information for cash-generating units [line items]            
Goodwill 13,440,470 428,450 13,489,766      
EMS Segment [Member]            
Disclosure of information for cash-generating units [line items]            
Goodwill 3,655,360 116,524 3,449,952      
All other segments [member]            
Disclosure of information for cash-generating units [line items]            
Goodwill $ 15,323 $ 488 $ 148,101