v3.26.1
Financial Instruments - Summary of Maturity Analysis for Derivative Financial Instruments (Detail)
$ in Thousands, $ in Thousands
Dec. 31, 2025
TWD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
TWD ($)
Less than 1 month [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled $ 136,737 $ 4,359 $ 315,330
Less than 1 month [member] | Forward exchange contracts [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Net settled 100,732 3,211 10,872
Gross settled (2,985) (95) 116,843
Less than 1 month [member] | Forward exchange contracts [member] | Inflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled 14,697,943 468,535 10,395,219
Less than 1 month [member] | Forward exchange contracts [member] | Outflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled (14,700,928) (468,630) (10,278,376)
Less than 1 month [member] | Swap contracts [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled 139,722 4,454 198,487
Less than 1 month [member] | Swap contracts [member] | Inflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled 19,403,174 618,526 13,901,338
Less than 1 month [member] | Swap contracts [member] | Outflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled (19,263,452) (614,072) (13,702,851)
1 to 3 months [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled (156,062) (4,975) 1,607,609
1 to 3 months [member] | Forward exchange contracts [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Net settled 37,542 1,197 11,550
Gross settled (10,738) (342) 35,233
1 to 3 months [member] | Forward exchange contracts [member] | Inflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled 1,903,349 60,674 3,866,536
1 to 3 months [member] | Forward exchange contracts [member] | Outflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled (1,914,087) (61,016) (3,831,303)
1 to 3 months [member] | Swap contracts [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled (145,324) (4,633) 1,572,376
1 to 3 months [member] | Swap contracts [member] | Inflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled 35,662,026 1,136,819 31,704,116
1 to 3 months [member] | Swap contracts [member] | Outflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled (35,807,350) (1,141,452) (30,131,740)
3 months to 1 year [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled 4,021,099 128,183 4,086,157
3 months to 1 year [member] | Forward exchange contracts [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Net settled 0 0  
Gross settled     12,463
3 months to 1 year [member] | Forward exchange contracts [member] | Inflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled 0 0 332,003
3 months to 1 year [member] | Forward exchange contracts [member] | Outflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled 0 0 (319,540)
3 months to 1 year [member] | Swap contracts [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled 4,021,099 128,183 4,073,694
3 months to 1 year [member] | Swap contracts [member] | Inflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled 84,672,420 2,699,153 84,978,720
3 months to 1 year [member] | Swap contracts [member] | Outflows [member]      
Disclosure of maturity analysis for derivative financial liabilities [line items]      
Gross settled $ (80,651,321) $ (2,570,970) $ (80,905,026)