v3.26.1
Financial Instruments - Summary of Fair Value of Financial Instruments that are Measured 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 mandatorily classified as at FVTPL $ 10,187,492 $ 324,753 $ 10,832,042
Unsecured cumulative subordinate corporate bonds 1,008,140 32,137 1,025,760
Trade receivables, net 6,182,804 197,093 6,532,508
Financial assets at FVTOCI 19,798,058 631,115 20,492,001
Financial liabilities at FVTPL 1,395,368 44,481 832,869
Derivative financial instruments [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities at FVTPL 825,420 26,312 243,752
Swap contracts [member] | Derivative financial instruments [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 3,412,108 108,770 4,282,512
Financial liabilities at FVTPL 736,231 23,469 179,967
Forward exchange contracts [member] | Derivative financial instruments [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 248,813 7,932 258,362
Financial liabilities at FVTPL 75,438 2,405 63,785
Quoted shares [member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 2,277,680 72,607 2,898,751
Private-placement funds [member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 1,435,095 45,747 1,503,382
Open-end mutual funds [member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 971,952 30,983 590,346
Unquoted preferred shares [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets at FVTOCI, Investments in equity instruments 12,408 396 14,808
Unquoted preferred shares [member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 822,065 26,205 863,484
Convertible notes [member] | Hybrid financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 345,730 11,021 360,635
Unquoted ordinary shares [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets at FVTOCI, Investments in equity instruments 12,546,772 399,961 12,846,151
Unquoted ordinary shares [member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 822,065 26,205 863,484
TIB quoted ordinary shares [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets at FVTOCI, Investments in equity instruments 47,934 1,528 72,774
Contingent considerations [member] | Derivative financial instruments [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities at FVTPL 569,948 18,169 589,117
Others [Member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 161,150 5,138 0
Others [Member] | Hybrid financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 15,000 478 74,570
Accumulator contracts [member] | Derivative financial instruments [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities at FVTPL 13,751 438 0
Equity-linked structured products[member] | Hybrid financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 497,899 15,872 0
Level 1 of fair value hierarchy [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 3,249,632 103,590 3,489,097
Financial assets at FVTOCI 47,934 1,528 72,774
Level 1 of fair value hierarchy [member] | Quoted shares [member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 2,277,680 72,607 2,898,751
Level 1 of fair value hierarchy [member] | Open-end mutual funds [member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 971,952 30,983 590,346
Level 1 of fair value hierarchy [member] | Unquoted preferred shares [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets at FVTOCI, Investments in equity instruments 0    
Level 1 of fair value hierarchy [member] | TIB quoted ordinary shares [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets at FVTOCI, Investments in equity instruments 47,934 1,528 72,774
Level 2 of fair value hierarchy [Member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 3,660,921 116,702 4,540,874
Financial liabilities at FVTPL 811,669 25,874 243,752
Level 2 of fair value hierarchy [Member] | Swap contracts [member] | Derivative financial instruments [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 3,412,108 108,770 4,282,512
Financial liabilities at FVTPL 736,231 23,469 179,967
Level 2 of fair value hierarchy [Member] | Forward exchange contracts [member] | Derivative financial instruments [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 248,813 7,932 258,362
Financial liabilities at FVTPL 75,438 2,405 63,785
Level 3 of fair value hierarchy [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 3,276,939 104,461 2,802,071
Unsecured cumulative subordinate corporate bonds 1,008,140 32,137 1,025,760
Trade receivables, net 6,182,804 197,093 6,532,508
Financial assets at FVTOCI 19,750,124 629,587 20,419,227
Financial liabilities at FVTPL 583,699 18,607 589,117
Level 3 of fair value hierarchy [member] | Quoted shares [member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 0    
Level 3 of fair value hierarchy [member] | Private-placement funds [member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 1,435,095 45,747 1,503,382
Level 3 of fair value hierarchy [member] | Unquoted preferred shares [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets at FVTOCI, Investments in equity instruments 12,408 396 14,808
Level 3 of fair value hierarchy [member] | Unquoted preferred shares [member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 822,065 26,205 863,484
Level 3 of fair value hierarchy [member] | Convertible notes [member] | Hybrid financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 345,730 11,021 360,635
Level 3 of fair value hierarchy [member] | Unquoted ordinary shares [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets at FVTOCI, Investments in equity instruments 12,546,772 399,961 12,846,151
Level 3 of fair value hierarchy [member] | Contingent considerations [member] | Derivative financial instruments [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities at FVTPL 569,948 18,169 589,117
Level 3 of fair value hierarchy [member] | Others [Member] | Non-derivative financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 161,150 5,138  
Level 3 of fair value hierarchy [member] | Others [Member] | Hybrid financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL 15,000 478 $ 74,570
Level 3 of fair value hierarchy [member] | Accumulator contracts [member] | Derivative financial instruments [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities at FVTPL 13,751 438  
Level 3 of fair value hierarchy [member] | Equity-linked structured products[member] | Hybrid financial assets [member]      
Disclosure of detailed information about financial instruments [line items]      
Financial assets mandatorily classified as at FVTPL $ 497,899 $ 15,872