v3.26.1
Retirement Benefit Plans - Additional Information (Detail)
$ in Thousands, $ in Thousands
12 Months Ended
Dec. 31, 2025
TWD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
TWD ($)
Dec. 31, 2023
TWD ($)
Dec. 31, 2025
USD ($)
Disclosure of defined benefit plans [line items]          
Percentage of monthly pension contributions 6.00% 6.00%      
Pension costs $ 204,554 $ 6,521 $ 213,990 $ 209,978  
Expected contribution to defined benefit plans     414,648    
Expected contribution to defined benefit plans in 2025 640,728 20,425      
Pension plans for executive managers [member]          
Disclosure of defined benefit plans [line items]          
Pension costs 7,659 244 10,434 11,898  
Accrued pension liabilities 389,792   381,020   $ 12,425
Gains (losses) on remeasurements of defined benefit plans $ 1,113 $ 35 $ 12,035 $ 954  
Bottom of range [member]          
Disclosure of defined benefit plans [line items]          
Average duration of the defined benefit obligation 5 years 5 years 6 years    
Top of range [member]          
Disclosure of defined benefit plans [line items]          
Average duration of the defined benefit obligation 12 years 12 years 12 years