v3.26.1
Contents of Significant Accounts - Property, Plant and Equipment (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 detailed information about property, plant and equipment [line items]        
Beginning balance $ 279,059,037      
Depreciation 56,427,377 $ 1,798,769 $ 45,472,102 $ 37,757,556
Ending balance 271,395,296 $ 8,651,428 279,059,037  
Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 277,344,422      
Ending balance 269,692,409   277,344,422  
Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 1,714,615      
Ending balance 1,702,887   1,714,615  
Cost [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 1,247,992,796   1,152,668,676  
Additions 46,160,529   76,547,787  
Disposals 3,223,711   2,273,676  
Disposal of a subsidiary     (159,686)  
Transfers and reclassifications 6,532,045   3,394,106  
Exchange effect (11,332,497)   17,815,589  
Ending balance 1,286,129,162   1,247,992,796 1,152,668,676
Cost [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 4,413,542   4,372,705  
Disposals (1,762)      
Transfers and reclassifications 49,944   17,166  
Exchange effect (13,610)   23,671  
Ending balance 4,448,114   4,413,542 4,372,705
Accumulated depreciation, amortisation and impairment [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance (970,648,374)   (915,292,122)  
Depreciation 55,666,456   44,720,023  
Disposals (3,217,047)   (2,226,859)  
Disposal of a subsidiary     (47,139)  
Exchange effect (6,661,030)   12,910,227  
Ending balance (1,016,436,753)   (970,648,374) (915,292,122)
Accumulated depreciation, amortisation and impairment [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance (2,698,927)   (2,626,011)  
Depreciation 55,212   53,428  
Disposals (988)      
Exchange effect (7,924)   19,488  
Ending balance (2,745,227)   (2,698,927) (2,626,011)
Land [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 1,410,796      
Ending balance 1,385,971   1,410,796  
Land [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 536,721      
Ending balance 532,934   536,721  
Land [member] | Cost [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 1,410,796   1,430,338  
Additions 0   0  
Disposals 0   0  
Disposal of a subsidiary     0  
Transfers and reclassifications 0   0  
Exchange effect (24,825)   (19,542)  
Ending balance 1,385,971   1,410,796 1,430,338
Land [member] | Cost [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 536,721   539,703  
Disposals 0      
Transfers and reclassifications 0   0  
Exchange effect (3,787)   (2,982)  
Ending balance 532,934   536,721 539,703
Land [member] | Accumulated depreciation, amortisation and impairment [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 0   0  
Depreciation 0   0  
Disposals 0   0  
Disposal of a subsidiary     0  
Exchange effect 0   0  
Ending balance 0   0 0
Land [member] | Accumulated depreciation, amortisation and impairment [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 0   0  
Depreciation 0   0  
Disposals 0      
Exchange effect 0   0  
Ending balance 0   0 0
Buildings [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 39,913,012      
Ending balance 39,595,520   39,913,012  
Buildings [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 1,113,806      
Ending balance 1,093,398   1,113,806  
Buildings [member] | Cost [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 65,588,012   38,369,863  
Additions 210,455   32,999  
Disposals 27,441   1,019  
Disposal of a subsidiary     (119,322)  
Transfers and reclassifications 2,908,510   26,772,957  
Exchange effect (1,272,200)   532,534  
Ending balance 67,407,336   65,588,012 38,369,863
Buildings [member] | Cost [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 2,461,012   2,440,917  
Disposals (1,250)      
Transfers and reclassifications 22,190   2,000  
Exchange effect (8,906)   18,095  
Ending balance 2,473,046   2,461,012 2,440,917
Buildings [member] | Accumulated depreciation, amortisation and impairment [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance (25,675,000)   (24,028,140)  
Depreciation 2,281,586   1,474,732  
Disposals (27,441)   (109)  
Disposal of a subsidiary     (27,083)  
Exchange effect (117,329)   199,320  
Ending balance (27,811,816)   (25,675,000) (24,028,140)
Buildings [member] | Accumulated depreciation, amortisation and impairment [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance (1,347,206)   (1,297,068)  
Depreciation 39,458   39,193  
Disposals (476)      
Exchange effect (6,540)   10,945  
Ending balance (1,379,648)   (1,347,206) (1,297,068)
Machinery and equipment [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 189,236,936      
Ending balance 198,939,453   189,236,936  
Machinery and equipment [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 0      
Ending balance 0   0  
Machinery and equipment [member] | Cost [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 1,126,546,727   1,021,498,821  
Additions 0   0  
Disposals 3,189,633   2,198,549  
Disposal of a subsidiary     0  
Transfers and reclassifications 63,912,986   93,484,809  
Exchange effect (8,002,570)   13,761,646  
Ending balance 1,179,267,510   1,126,546,727 1,021,498,821
Machinery and equipment [member] | Cost [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 6,345   6,345  
Disposals 0      
Transfers and reclassifications 0   0  
Exchange effect 0   0  
Ending balance 6,345   6,345 6,345
Machinery and equipment [member] | Accumulated depreciation, amortisation and impairment [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance (937,309,791)   (884,088,674)  
Depreciation 52,737,289   42,716,755  
Disposals (3,182,973)   (2,153,787)  
Disposal of a subsidiary     0  
Exchange effect (6,536,050)   12,658,149  
Ending balance (980,328,057)   (937,309,791) (884,088,674)
Machinery and equipment [member] | Accumulated depreciation, amortisation and impairment [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance (6,345)   (6,345)  
Depreciation 0   0  
Disposals 0      
Exchange effect 0   0  
Ending balance (6,345)   (6,345) (6,345)
Transportation equipment [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 16,287      
Ending balance 16,261   16,287  
Transportation equipment [member] | Cost [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 78,020   71,712  
Additions 0   0  
Disposals 550   0  
Disposal of a subsidiary     0  
Transfers and reclassifications 4,388   5,087  
Exchange effect (702)   1,221  
Ending balance 81,156   78,020 71,712
Transportation equipment [member] | Accumulated depreciation, amortisation and impairment [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance (61,733)   (56,257)  
Depreciation 4,096   4,663  
Disposals (550)   0  
Disposal of a subsidiary     0  
Exchange effect (384)   813  
Ending balance (64,895)   (61,733) (56,257)
Furniture and fixtures [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 1,998,846      
Ending balance 2,787,686   1,998,846  
Furniture and fixtures [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 64,088      
Ending balance 76,555   64,088  
Furniture and fixtures [member] | Cost [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 9,533,232   8,873,468  
Additions 0   0  
Disposals 6,087   73,357  
Disposal of a subsidiary     (40,364)  
Transfers and reclassifications 1,417,913   717,154  
Exchange effect 7,477   56,331  
Ending balance 10,952,535   9,533,232 8,873,468
Furniture and fixtures [member] | Cost [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 1,409,464   1,385,740  
Disposals (512)      
Transfers and reclassifications 27,754   15,166  
Exchange effect (917)   8,558  
Ending balance 1,435,789   1,409,464 1,385,740
Furniture and fixtures [member] | Accumulated depreciation, amortisation and impairment [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance (7,534,386)   (7,056,013)  
Depreciation 641,419   521,994  
Disposals (6,083)   (72,920)  
Disposal of a subsidiary     (20,056)  
Exchange effect (4,873)   49,355  
Ending balance (8,164,849)   (7,534,386) (7,056,013)
Furniture and fixtures [member] | Accumulated depreciation, amortisation and impairment [member] | Operating Leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance (1,345,376)   (1,322,598)  
Depreciation 15,754   14,235  
Disposals (512)      
Exchange effect (1,384)   8,543  
Ending balance (1,359,234)   (1,345,376) (1,322,598)
Leasehold improvement [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 943      
Ending balance 954   943  
Leasehold improvement [member] | Cost [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 68,407   65,823  
Additions 0   0  
Disposals 0   43  
Disposal of a subsidiary     0  
Transfers and reclassifications 2,141   0  
Exchange effect (2,458)   2,627  
Ending balance 68,090   68,407 65,823
Leasehold improvement [member] | Accumulated depreciation, amortisation and impairment [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance (67,464)   (63,038)  
Depreciation 2,066   1,879  
Disposals 0   (43)  
Disposal of a subsidiary     0  
Exchange effect (2,394)   2,590  
Ending balance (67,136)   (67,464) (63,038)
Construction in progress and equipment awaiting inspection [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 44,767,602      
Ending balance 26,966,564   44,767,602  
Construction in progress and equipment awaiting inspection [member] | Cost [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 44,767,602   82,358,651  
Additions 45,950,074   76,514,788  
Disposals 0   708  
Disposal of a subsidiary     0  
Transfers and reclassifications (61,713,893)   (117,585,901)  
Exchange effect (2,037,219)   3,480,772  
Ending balance 26,966,564   44,767,602 82,358,651
Construction in progress and equipment awaiting inspection [member] | Accumulated depreciation, amortisation and impairment [member] | Property, plant and equipment not subject to operating leases [member]        
Disclosure of detailed information about property, plant and equipment [line items]        
Beginning balance 0   0  
Depreciation 0   0  
Disposals 0   0  
Disposal of a subsidiary     0  
Exchange effect 0   0  
Ending balance $ 0   $ 0 $ 0