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Contents of Significant Accounts - Details of Investments Accounted for Under the Equity Method (Detail) $ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023 TWD ($)	Dec. 31, 2022 TWD ($)	Dec. 31, 2023 USD ($)
Investments in associates and joint ventures [line items]
Amount	$ 32,785,800	$ 26,504,913	$ 1,070,731
SILICON INTEGRATED SYSTEMS CORP. (SIS) [member]
Investments in associates and joint ventures [line items]
Amount	$ 2,373,060	$ 0
Percentage of ownership or voting rights, Associates	19.02%	0.00%
FARADAY TECHNOLOGY CORP. (FARADAY) [member]
Investments in associates and joint ventures [line items]
Amount	$ 1,990,073	$ 1,862,245
Percentage of ownership or voting rights, Associates	13.78%	13.78%
UNIMICRON TECHNOLOGY CORP. (UNIMICRON) [member]
Investments in associates and joint ventures [line items]
Amount	$ 13,644,560	$ 13,285,169
Percentage of ownership or voting rights, Associates	13.05%	13.27%
MTIC HOLDINGS PTE. LTD. [member]
Investments in associates and joint ventures [line items]
Amount	$ 0	$ 0
Percentage of ownership or voting rights, Associates	45.44%	45.44%
UNITECH CAPITAL INC. [member]
Investments in associates and joint ventures [line items]
Amount	$ 625,667	$ 426,070
Percentage of ownership or voting rights, Associates	42.00%	42.00%
TRIKNIGHT CAPITAL CORPORATION (TRIKNIGHT) [member]
Investments in associates and joint ventures [line items]
Amount	$ 2,109,906	$ 2,117,678
Percentage of ownership or voting rights, Associates	40.00%	40.00%
HSUN CHIEH CAPITAL CORP. [member]
Investments in associates and joint ventures [line items]
Amount	$ 235,098	$ 210,690
Percentage of ownership or voting rights, Associates	40.00%	40.00%
PURIUMFIL INC. [member]
Investments in associates and joint ventures [line items]
Amount	$ 11,474	$ 14,622
Percentage of ownership or voting rights, Associates	40.00%	40.00%
HSUN CHIEH INVESTMENT CO., LTD. (HSUN CHIEH) [member]
Investments in associates and joint ventures [line items]
Amount	$ 4,126,878	$ 2,980,984
Percentage of ownership or voting rights, Associates	36.49%	36.49%
YANN YUAN INVESTMENT CO., LTD. (YANN YUAN) [member]
Investments in associates and joint ventures [line items]
Amount	$ 7,516,327	$ 5,455,743
Percentage of ownership or voting rights, Associates	26.78%	26.78%
UNITED LED CORPORATION HONG KONG LIMITED [member]
Investments in associates and joint ventures [line items]
Amount	$ 93,793	$ 97,156
Percentage of ownership or voting rights, Associates	25.14%	25.14%
VSENSE CO., LTD. [member]
Investments in associates and joint ventures [line items]
Amount	$ 0	$ 0
Percentage of ownership or voting rights, Associates	23.98%	23.98%
TRANSLINK CAPITAL PARTNERS I, L.P. [member]
Investments in associates and joint ventures [line items]
Amount	$ 58,964	$ 54,556
Percentage of ownership or voting rights, Associates	10.38%	10.38%

X

- Definition

The amount of investments accounted for using the equity method. The equity method is a method of accounting whereby the investment is initially recognised at cost and adjusted thereafter for the post-acquisition change in the investor's share of net assets of the investee. The investor's profit or loss includes its share of the profit or loss of the investee. The investor's other comprehensive income includes its share of the other comprehensive income of the investee. [Refer: At cost [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2023-01-01
-Paragraph 24
-Subparagraph a
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-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
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-IssueDate 2023-01-01
-Paragraph B16
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2023-en-r&anchor=para_B16&doctype=Appendix&subtype=B
-URIDate 2023-03-23

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-IssueDate 2023-01-01
-Paragraph 54
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-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_54_e&doctype=Standard
-URIDate 2023-03-23

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- Definition

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2023-01-01
-Paragraph 17
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-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
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-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=27&code=ifrs-tx-2023-en-r&anchor=para_16_b_iii&doctype=Standard
-URIDate 2023-03-23

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
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-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2023-en-r&anchor=para_21_a_iv&doctype=Standard
-URIDate 2023-03-23

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