v3.26.1
Contents of Significant Accounts - Summary of Information about Provisions of Liabilities (Detail)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
TWD ($)
Others  
Disclosure of other provisions [line items]  
Balance as of January 1, 2025 $ 0
Arising during the period 68,899
Unused provision reversed 0
Discount rate adjustment and unwinding of discount from the passage of time 0
Exchange effect 303
Balance as of December 31, 2025 69,202
Onerous Contracts [member]  
Disclosure of other provisions [line items]  
Balance as of January 1, 2025 281,244
Arising during the period 84,324
Unused provision reversed (203,266)
Discount rate adjustment and unwinding of discount from the passage of time 0
Exchange effect (2,188)
Balance as of December 31, 2025 160,114
Decommissioning Liabilities [member]  
Disclosure of other provisions [line items]  
Balance as of January 1, 2025 695,168
Arising during the period 155,245
Unused provision reversed 0
Discount rate adjustment and unwinding of discount from the passage of time 75,027
Exchange effect (27,167)
Balance as of December 31, 2025 $ 898,273