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Contents of Significant Accounts - Summary of Terms and Conditions of Bonds (Detail) - TWD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2024 | Dec. 31, 2023
Disclosure of detailed information about bonds [Line Items] |  |
Issued amount | $ 30,051,568 | $ 38,359,352
Domestic unsecured corporate bonds maturing in June 2024 [member] |  |
Disclosure of detailed information about bonds [Line Items] |  |
Term | Ten-year |
Issuance date | In mid-June 2014 |
Issued amount | $ 3,000,000 |
Coupon rate | 1.95% |
Repayment | Interest was paid annually and the principal was fully repaid in June 2024. |
Domestic unsecured corporate bonds maturing in March 2024 [member] |  |
Disclosure of detailed information about bonds [Line Items] |  |
Term | Seven-year |
Issuance date | In late March 2017 |
Issued amount | $ 2,100,000 |
Coupon rate | 1.43% |
Repayment | Interest was paid annually and the principal was fully repaid in March 2024. |
Domestic unsecured corporate bonds maturing in October 2024 [member] |  |
Disclosure of detailed information about bonds [Line Items] |  |
Term | Seven-year |
Issuance date | In early October 2017 |
Issued amount | $ 3,400,000 |
Coupon rate | 1.13% |
Repayment | Interest was paid annually and the principal was fully repaid in October 2024. |
Domestic unsecured corporate bonds maturing in April 2026 [Member] |  |
Disclosure of detailed information about bonds [Line Items] |  |
Term | Five-year |
Issuance date | In late April 2021 |
Issued amount | $ 5,500,000 |
Coupon rate | 0.57% |
Repayment | Interest will be paid annually and the principal will be repayable in April 2026 upon maturity. |
Domestic unsecured corporate bonds maturing in April 2028 [Member] |  |
Disclosure of detailed information about bonds [Line Items] |  |
Term | Seven-year |
Issuance date | In late April 2021 |
Issued amount | $ 2,000,000 |
Coupon rate | 0.63% |
Repayment | Interest will be paid annually and the principal will be repayable in April 2028 upon maturity. |
Domestic unsecured corporate bonds maturing in April 2031 [Member] |  |
Disclosure of detailed information about bonds [Line Items] |  |
Term | Ten-year (Green bond) |
Issuance date | In late April 2021 |
Issued amount | $ 2,100,000 |
Coupon rate | 0.68% |
Repayment | Interest will be paid annually and the principal will be repayable in April 2031 upon maturity. |
Domestic unsecured corporate bonds maturing in December 2026 [member] |  |
Disclosure of detailed information about bonds [Line Items] |  |
Term | Five-year |
Issuance date | In mid-December 2021 |
Issued amount | $ 5,000,000 |
Coupon rate | 0.63% |
Repayment | Interest will be paid annually and the principal will be repayable in December 2026 upon maturity. |
Domestic unsecured corporate bonds maturing In September 2028 [Member] |  |
Disclosure of detailed information about bonds [Line Items] |  |
Term | Five-year (Green bond) |
Issuance date | In mid-September 2023 |
Issued amount | $ 10,000,000 |
Coupon rate | 1.62% |
Repayment | Interest will be paid annually and the principal will be repayable in September 2028 upon maturity. |

X
- Definition The amount of bonds issued by the entity. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 112 -Subparagraph c -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_112_c&doctype=Standard -URIDate 2024-03-27 + Details
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