v3.26.1
Financial Risk and Fair Value Disclosures - Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis (Detail)
$ in Thousands, $ in Thousands
Dec. 31, 2025
TWD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
TWD ($)
Disclosure of detailed information about financial instruments [line items]      
Financial assets at fair value through profit or loss, current $ 568,521 $ 18,123 $ 606,018
Financial assets at fair value through profit or loss, noncurrent 17,585,395 560,580 17,850,914
Financial assets at fair value through other comprehensive income, current 4,630,441 147,607 5,893,377
Financial assets at fair value through other comprehensive income, noncurrent 9,144,308 291,499 11,315,951
Financial liabilities at fair value through profit or loss, current 57,163 $ 1,822 901,000
Level 1 [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets at fair value through profit or loss, current 468,010   606,016
Financial assets at fair value through profit or loss, noncurrent 5,838,381   5,703,325
Financial assets at fair value through other comprehensive income, current 4,630,441   5,893,377
Financial assets at fair value through other comprehensive income, noncurrent 5,990,762   7,879,553
Financial liabilities at fair value through profit or loss, current 0   0
Level 2 [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets at fair value through profit or loss, current 1,859   2
Financial assets at fair value through profit or loss, noncurrent 20,600   18,800
Financial assets at fair value through other comprehensive income, current 0   0
Financial assets at fair value through other comprehensive income, noncurrent 0   0
Financial liabilities at fair value through profit or loss, current 2,512   1,039
Level 3 [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets at fair value through profit or loss, current 98,652   0
Financial assets at fair value through profit or loss, noncurrent 11,726,414   12,128,789
Financial assets at fair value through other comprehensive income, current 0   0
Financial assets at fair value through other comprehensive income, noncurrent 3,153,546   3,436,398
Financial liabilities at fair value through profit or loss, current $ 54,651   $ 899,961