v3.26.1
Financial Instruments - Summary of Financial Assets Measured at Level 3 Fair Value (Detail)
$ in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2025
TWD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
TWD ($)
Dec. 31, 2023
TWD ($)
Disclosure of fair value measurement of assets [line items]        
Beginning Balance $ 741,060,069      
Net increase (decrease) in trade receivables (11,899,300) $ (379,321) $ (14,331,791) $ 15,868,810
Ending Balance 889,499,758 28,355,108 741,060,069  
Available-for-sale [member] | Level 3 of fair value hierarchy [member]        
Disclosure of fair value measurement of assets [line items]        
Beginning Balance 23,221,298 740,238 9,906,607 9,565,566
Recognized in profit or loss 119,211 3,800 (343,820) (83,352)
Recognized in other comprehensive income (Unrealized gains (losses) on financial assets at FVTOCI) (225,266) (7,181) (26,543) 199,107
Recognized in other comprehensive income (Effects of foreign currency exchange) (640,470) (20,417) 476,406 6,658
Net increase (decrease) in trade receivables (349,704) (11,147) 2,062,310 6,012,850
Effects of foreign currency exchange   11    
Trade receivables factored     (1,167,287) (5,778,078)
Transferred out of Level 3     (53,360)  
Acquisition through business combinations 357      
Reclassification 30,639 977    
Purchases 2,805,240 89,425 12,691,798 883,774
Disposals (1,934,242) (61,658) (324,813) (870,346)
Ending Balance 23,027,063 734,048 23,221,298 9,906,607
Available-for-sale [member] | Level 3 of fair value hierarchy [member] | Disposal of subsidiary [member]        
Disclosure of fair value measurement of assets [line items]        
Disposals       (29,572)
Available-for-sale [member] | Level 3 of fair value hierarchy [member] | FVTPL equity instrument [member]        
Disclosure of fair value measurement of assets [line items]        
Beginning Balance 2,366,866 75,450 2,543,975 2,666,264
Recognized in profit or loss 196,009 6,248 (352,120) (83,239)
Recognized in other comprehensive income (Unrealized gains (losses) on financial assets at FVTOCI)   0    
Recognized in other comprehensive income (Effects of foreign currency exchange) (95,920) (3,058) 137,556 5,053
Net increase (decrease) in trade receivables   0    
Effects of foreign currency exchange   0    
Reclassification 30,639 977    
Purchases 194,150 6,189 177,813 637,767
Disposals (273,434) (8,716) (140,358) (681,870)
Ending Balance 2,418,310 77,090 2,366,866 2,543,975
Available-for-sale [member] | Level 3 of fair value hierarchy [member] | FVTPL debt instrument [member]        
Disclosure of fair value measurement of assets [line items]        
Net increase (decrease) in trade receivables     1,167,287 5,778,078
Trade receivables factored     (1,167,287) (5,778,078)
Available-for-sale [member] | Level 3 of fair value hierarchy [member] | FVTPL hybrid instruments [member]        
Disclosure of fair value measurement of assets [line items]        
Beginning Balance 435,205 13,873 61,410  
Recognized in profit or loss (76,798) (2,448) 8,300 (113)
Recognized in other comprehensive income (Unrealized gains (losses) on financial assets at FVTOCI)   0    
Recognized in other comprehensive income (Effects of foreign currency exchange) (4,818) (154) 2,270  
Net increase (decrease) in trade receivables   0    
Effects of foreign currency exchange   0    
Reclassification   0    
Purchases 2,132,740 67,987 363,225 61,523
Disposals (1,627,700) (51,887)    
Ending Balance 858,629 27,371 435,205 61,410
Available-for-sale [member] | Level 3 of fair value hierarchy [member] | FVOCI equity instruments [member]        
Disclosure of fair value measurement of assets [line items]        
Beginning Balance 12,860,959 409,976 620,831 436,876
Recognized in profit or loss   0    
Recognized in other comprehensive income (Unrealized gains (losses) on financial assets at FVTOCI) (207,646) (6,619) (9,397) 215,914
Recognized in other comprehensive income (Effects of foreign currency exchange) (539,732) (17,205) 336,580 1,605
Net increase (decrease) in trade receivables   0    
Effects of foreign currency exchange   11    
Transferred out of Level 3     (53,360)  
Acquisition through business combinations 357      
Reclassification   0    
Purchases 478,350 15,249 12,150,760 184,484
Disposals (33,108) (1,055) (184,455) (188,476)
Ending Balance 12,559,180 400,357 12,860,959 620,831
Available-for-sale [member] | Level 3 of fair value hierarchy [member] | FVOCI equity instruments [member] | Disposal of subsidiary [member]        
Disclosure of fair value measurement of assets [line items]        
Disposals       (29,572)
Available-for-sale [member] | Level 3 of fair value hierarchy [member] | FVOCI debt instruments [member]        
Disclosure of fair value measurement of assets [line items]        
Beginning Balance 7,558,268 240,939 6,680,391 6,462,426
Recognized in profit or loss   0    
Recognized in other comprehensive income (Unrealized gains (losses) on financial assets at FVTOCI) (17,620) (562) (17,146) (16,807)
Recognized in other comprehensive income (Effects of foreign currency exchange)   0    
Net increase (decrease) in trade receivables (349,704) (11,147) 895,023 234,772
Effects of foreign currency exchange   0    
Reclassification   0    
Purchases   0    
Disposals   0    
Ending Balance $ 7,190,944 $ 229,230 $ 7,558,268 $ 6,680,391