Financial Instruments - Summary of Detailed Information about Maturity Analysis of Obligation under Leases (Detail) $ in Thousands, $ in Thousands	Dec. 31, 2025 TWD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2024 TWD ($)
Less than 1 year [member] \| Obligation under leases [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Non-derivative financial liabilities undiscounted amounts	$ 1,180,893	$ 37,645	$ 1,154,737
1-5 years [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Non-derivative financial liabilities undiscounted amounts	253,157,381	8,070,047	146,133,980
1-5 years [member] \| Obligation under leases [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Non-derivative financial liabilities undiscounted amounts	3,048,712	97,186	2,676,514
5 to 10 Years [member] \| Obligation under leases [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Non-derivative financial liabilities undiscounted amounts	1,817,587	57,940	1,964,781
10 to 15 Years [member] \| Obligation under leases [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Non-derivative financial liabilities undiscounted amounts	1,281,842	40,862	951,983
15 to 20 Years [member] \| Obligation under leases [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Non-derivative financial liabilities undiscounted amounts	1,203,233	38,356	917,034
More than 20 Years [member] \| Obligation under leases [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Non-derivative financial liabilities undiscounted amounts	$ 3,081,832	$ 98,242	$ 1,738,240