The gains (losses) recognised in other comprehensive income on exchange differences on the translation of financial statements of foreign operations, net of tax, before reclassification adjustments. [Refer: Other comprehensive income]

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Contents of Significant Accounts - Investments Accounted For Under the Equity Method - Additional Information (Detail) $ in Thousands, $ in Thousands		12 Months Ended
	Jan. 06, 2023 shares	Dec. 31, 2025 TWD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2024 TWD ($)	Dec. 31, 2023 TWD ($)	Dec. 31, 2025 USD ($)	Jul. 31, 2024 TWD ($)
Investments in associates [Line Items]
Investments accounted for using equity method for which there are published price quotations		$ 36,869,092		$ 33,274,869		$ 1,175,298
Proceeds from capital reduction of investments accounted for under the equity method		574,997	$ 18,330	1,601,874	$ 1,303,106
Silicon integrated systems corp [Member]
Investments in associates [Line Items]
Capital Reduction And Refunded On Investment Accounted For Using Equity Method							$ 499,000
HSUN CHIEH INVESTMENT CO., LTD. (HSUN CHIEH) [member]
Investments in associates [Line Items]
Investments accounted for using equity method for which there are published price quotations		4,855,031		4,723,930
Proceeds from capital reduction of investments accounted for under the equity method		343,000		343,000
TRIKNIGHT CAPITAL CORPORATION (TRIKNIGHT) [member]
Investments in associates [Line Items]
Investments accounted for using equity method for which there are published price quotations		759,446		1,298,112
Proceeds from capital reduction of investments accounted for under the equity method		232,000		760,000
UNIMICRON TECHNOLOGY CORP. (UNIMICRON) [member]
Investments in associates [Line Items]
Investments accounted for using equity method for which there are published price quotations		14,388,815		13,824,584
UNIMICRON TECHNOLOGY CORP. (UNIMICRON) [member] \| SUBTRON TECHNOLOGY CO., LTD. (SUBTRON) [member]
Investments in associates [Line Items]
Number of shares exchanged \| shares	23,000,000
Number of shares allotted \| shares	5,000,000
Share exchange description	1 common share of SUBTRON to exchange 0.219 common shares of UNIMICRON
Aggregated individually immaterial associates [member]
Investments in associates [Line Items]
Exchange differences arising from translation of the foreign entity		(34,000)		55,000	$ (3,000)
Investments with published price quotations [member]
Investments in associates [Line Items]
Investments accounted for using equity method for which there are published price quotations		19,142,000		18,231,000
Investments with published price quotations [member] \| Fair value [member]
Investments in associates [Line Items]
Investments accounted for using equity method for which there are published price quotations		$ 54,202,000		$ 43,305,000