v3.26.1
Contents of Significant Accounts - Intangible Assets (Detail)
$ in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2025
TWD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
TWD ($)
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance $ 4,154,315    
Ending balance 4,742,876 $ 151,191 $ 4,154,315
Net carrying amount:      
Intangible assets 4,742,876   4,154,315
Cost [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance 10,485,262   10,565,271
Additions 3,350,984   2,284,641
Write-off (2,994,824)   (2,720,083)
Disposal of a subsidiary     (3,151)
Acquisition of a subsidiary 19,565    
Reclassifications     7,363
Exchange effect (25,032)   351,221
Ending balance 10,835,955   10,485,262
Net carrying amount:      
Intangible assets 10,835,955   10,485,262
Accumulated amortisation and impairment [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance (6,330,947)   (6,192,716)
Amortization 2,751,507   2,636,538
Write-off (2,994,824)   (2,720,083)
Disposal of a subsidiary     (2,025)
Exchange effect 5,449   223,801
Ending balance (6,093,079)   (6,330,947)
Net carrying amount:      
Intangible assets (6,093,079)   (6,330,947)
Goodwill [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance 7,614    
Ending balance 27,179   7,614
Net carrying amount:      
Intangible assets 27,179   7,614
Goodwill [member] | Cost [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance 15,012   15,012
Additions 0   0
Write-off 0   0
Disposal of a subsidiary     0
Acquisition of a subsidiary 19,565    
Reclassifications     0
Exchange effect 0   0
Ending balance 34,577   15,012
Net carrying amount:      
Intangible assets 34,577   15,012
Goodwill [member] | Accumulated amortisation and impairment [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance (7,398)   (7,398)
Amortization 0   0
Write-off 0   0
Disposal of a subsidiary     0
Exchange effect 0   0
Ending balance (7,398)   (7,398)
Net carrying amount:      
Intangible assets (7,398)   (7,398)
Software [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance 2,245,384    
Ending balance 2,913,625   2,245,384
Net carrying amount:      
Intangible assets 2,913,625   2,245,384
Software [member] | Cost [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance 5,476,499   5,466,077
Additions 2,450,285   1,328,781
Write-off (2,221,557)   (1,290,196)
Disposal of a subsidiary     (3,151)
Acquisition of a subsidiary 0    
Reclassifications     7,363
Exchange effect (73,952)   (32,375)
Ending balance 5,631,275   5,476,499
Net carrying amount:      
Intangible assets 5,631,275   5,476,499
Software [member] | Accumulated amortisation and impairment [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance (3,231,115)   (2,890,831)
Amortization 1,736,793   1,656,180
Write-off (2,221,557)   (1,290,196)
Disposal of a subsidiary     (2,025)
Exchange effect (28,701)   (23,675)
Ending balance (2,717,650)   (3,231,115)
Net carrying amount:      
Intangible assets (2,717,650)   (3,231,115)
Patent and technology license fee [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance 879,682    
Ending balance 659,702   879,682
Net carrying amount:      
Intangible assets 659,702   879,682
Patent and technology license fee [member] | Cost [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance 2,042,479   1,773,541
Additions 7,684   95,245
Write-off (259,094)   (214,874)
Disposal of a subsidiary     0
Acquisition of a subsidiary 0    
Reclassifications     0
Exchange effect 54,411   388,567
Ending balance 1,845,480   2,042,479
Net carrying amount:      
Intangible assets 1,845,480   2,042,479
Patent and technology license fee [member] | Accumulated amortisation and impairment [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance (1,162,797)   (908,965)
Amortization 241,726   216,437
Write-off (259,094)   (214,874)
Disposal of a subsidiary     0
Exchange effect 40,349   252,269
Ending balance (1,185,778)   (1,162,797)
Net carrying amount:      
Intangible assets (1,185,778)   (1,162,797)
Others [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance 1,021,635    
Ending balance 1,142,370   1,021,635
Net carrying amount:      
Intangible assets 1,142,370   1,021,635
Others [member] | Cost [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance 2,951,272   3,310,641
Additions 893,015   860,615
Write-off (514,173)   (1,215,013)
Disposal of a subsidiary     0
Acquisition of a subsidiary 0    
Reclassifications     0
Exchange effect (5,491)   (4,971)
Ending balance 3,324,623   2,951,272
Net carrying amount:      
Intangible assets 3,324,623   2,951,272
Others [member] | Accumulated amortisation and impairment [member]      
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]      
Beginning balance (1,929,637)   (2,385,522)
Amortization 772,988   763,921
Write-off (514,173)   (1,215,013)
Disposal of a subsidiary     0
Exchange effect (6,199)   (4,793)
Ending balance (2,182,253)   (1,929,637)
Net carrying amount:      
Intangible assets $ (2,182,253)   $ (1,929,637)