v3.26.1
Assets Pledged as Collateral - Summary of Assets Pledged as Collateral (Detail) - TWD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Assets Pledged As Collateral [Line Items]    
Assets pledged as collateral $ 2,134,962 $ 10,570,318
Refundable deposits time deposit [member] | Customs [member]    
Assets Pledged As Collateral [Line Items]    
Assets pledged as collateral $ 1,013,289 1,009,000
Purpose of pledge Customs duty guarantee  
Refundable deposits time deposit [member] | Science Park Bureau [member]    
Assets Pledged As Collateral [Line Items]    
Assets pledged as collateral $ 248,061 237,051
Purpose of pledge Collateral for land lease  
Refundable deposits time deposit [member] | Science Park Bureau [member] | Dormitory Lease [member]    
Assets Pledged As Collateral [Line Items]    
Assets pledged as collateral $ 18,647 18,647
Purpose of pledge Collateral for dormitory lease  
Refundable deposits time deposit [member] | National Property Administration, Ministry of Finance [member]    
Assets Pledged As Collateral [Line Items]    
Assets pledged as collateral $ 25,589 64,950
Purpose of pledge Guarantee for the application of national non-public use land for development  
Refundable deposits time deposit [member] | Bureau of Land Administration, Tainan City Government [Member]    
Assets Pledged As Collateral [Line Items]    
Assets pledged as collateral $ 0 8,118
Purpose of pledge Guarantee for the application of national non-public use land for development  
Refundable deposits time deposit [member] | Liquefied Natural Gas Business Division, CPC Corporation, Taiwan [member]    
Assets Pledged As Collateral [Line Items]    
Assets pledged as collateral $ 39,533 38,073
Purpose of pledge Energy resources guarantee  
Refundable deposits time deposit [member] | CTBC Bank Singapore Branch [member]    
Assets Pledged As Collateral [Line Items]    
Assets pledged as collateral $ 219,450 490,950
Purpose of pledge Collateral for letter of credit  
Buildings [member] | Taiwan Cooperative Bank and Secured Syndicated Loans from China Development Bank and 6 others [member]    
Assets Pledged As Collateral [Line Items]    
Assets pledged as collateral $ 69,303 4,377,176
Purpose of pledge Collateral for long-term loans  
Machinery and equipment [member] | Taiwan Cooperative Bank, Mega International Commercial Bank, KGI Bank, First Commercial Bank, Shanghai Commercial Bank, CTBC Bank and Secured Syndicated Loans from China Development Bank and 6 others [member]    
Assets Pledged As Collateral [Line Items]    
Assets pledged as collateral $ 501,090 4,057,201
Purpose of pledge Collateral for long-term loans  
Right-of-use assets [member] | Secured Syndicated Loans from China Development Bank and 6 others [member]    
Assets Pledged As Collateral [Line Items]    
Assets pledged as collateral $ 0 $ 269,152
Purpose of pledge Collateral for long-term loans