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Financial Statements Schedule: Valuation and Qualifying Accounts (Detail) - TWD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Allowance for Impairment of property, plant and equipment [member] |  |  |
Disclosure of details of valuation and qualifying accounts [Line Items] |  |  |
January 1 | $ 194,467 | $ 183,179 | $ 182,002
Additions charged to expense or deduction of revenue | 9,236 | 12,721 | 4,843
Deduction/Write-offs/Reversal |  | (1,433) | (3,666)
December 31 | 203,703 | 194,467 | 183,179
Allowance for Impairment of Obsolescence and Decline in Market Value of Inventories [Member] |  |  |
Disclosure of details of valuation and qualifying accounts [Line Items] |  |  |
January 1 | 105,630 | 121,586 | 79,815
Additions charged to expense or deduction of revenue | 80,633 |  | 41,771
Deduction/Write-offs/Reversal |  | (15,956) |
December 31 | 186,263 | 105,630 | 121,586
Provision for deficiency compensation [member] |  |  |
Disclosure of details of valuation and qualifying accounts [Line Items] |  |  |
January 1 | 26,643 | 4,281 | 3,463
Additions charged to expense or deduction of revenue | 21,495 | 79,827 | 11,898
Deduction/Write-offs/Reversal | (14,574) | (57,465) | (11,080)
December 31 | 33,564 | 26,643 | 4,281
Sales for allowance [member] |  |  |
Disclosure of details of valuation and qualifying accounts [Line Items] |  |  |
January 1 | 37,123 | 9,849 | 9,864
Additions charged to expense or deduction of revenue | 112,488 | 94,641 | 34,744
Deduction/Write-offs/Reversal | (111,944) | (67,367) | (34,759)
December 31 | $ 37,667 | $ 37,123 | $ 9,849

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