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Bonds Payable - Summary of Major Terms of Unsecured Domestic Bonds Issued (Detail) $ in Millions | 12 Months Ended
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Dec. 31, 2020 TWD ($)
Disclosure Of Detailed Information About Bonds Payable [Line Items] |
Total Amount | $ 20,000
Unsecured Domestic Bonds [Member] | Tranche A [Member] |
Disclosure Of Detailed Information About Bonds Payable [Line Items] |
Issuance | 2020-1
Issuance Period | July 2020 to July 2025
Total Amount | $ 8,800
Interest rates of loans | 0.50%
Repayment and Interest Payment | One-time repayment upon maturity; interest payable annually
Unsecured Domestic Bonds [Member] | Tranche B [Member] |
Disclosure Of Detailed Information About Bonds Payable [Line Items] |
Issuance Period | July 2020 to July 2027
Total Amount | $ 7,500
Interest rates of loans | 0.54%
Repayment and Interest Payment | The same as above
Unsecured Domestic Bonds [Member] | Tranche C [Member] |
Disclosure Of Detailed Information About Bonds Payable [Line Items] |
Issuance Period | July 2020 to July 2030
Total Amount | $ 3,700
Interest rates of loans | 0.59%
Repayment and Interest Payment | The same as above

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