Contents of Significant Accounts - Summary of Details on Derecognition of Such Investments (Detail) - TWD ($) $ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disposed and Derecognized Investments Designated as Fair Value Through Other Comprehensive Income [Abstract]
Fair value on the date of disposal	$ 0	$ 3,035,999	$ 0
Cumulative gains (losses) reclassified to retained earnings due to derecognition	$ 0	$ (1,628,388)	$ 0

The cumulative gain (loss) on disposal of investments in equity instruments that the entity has designated at fair value through other comprehensive income. [Refer: At fair value [member]; Other comprehensive income]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 11B
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_11B_c&doctype=Standard
-URIDate 2024-03-27

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration