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Net Income - Impairment Loss (Reversal of Impairment Loss) on Financial Instruments and Non-financial Assets (Detail) $ in Millions, $ in Millions | 12 Months Ended
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Dec. 31, 2020 TWD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 TWD ($) | Dec. 31, 2018 TWD ($)
Disclosure Of Impairment Loss And Reversal Of Impairment Loss [Abstract] |  |  |  |
Contract assets | $ 1 |  | $ (2) | $ 19
Trade notes and accounts receivable | 49 |  | (54) | 805
Other receivables | (5) |  | (69) | 96
Inventories | 1,161 | $ 41 | 475 | 365
Property, plant and equipment | 0 |  | 93 | 0
Investment properties | (27) | (1) | (57) | (19)
Intangible assets | 9 | 0 | 9 | 51
Other assets | $ 0 | $ 0 | $ 44 | $ 0

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- Definition Impairment loss on other assets. + References No definition available. + Details
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- Definition Impairment loss (reversal of impairment loss) recognised in profit or loss other receivables. + References No definition available. + Details
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- Definition Impairment loss (reversal) on receivables or contract assets arising from contracts with customers. + References No definition available. + Details
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- Definition The amount of impairment loss recognised in profit or loss for intangible assets and goodwill. [Refer: Impairment loss recognised in profit or loss; Intangible assets and goodwill] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 38 -IssueDate 2020-01-01 -Paragraph 118 -Subparagraph e -Clause iv -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=38&code=ifrs-tx-2020-en-r&anchor=para_118_e_iv&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The amount of impairment loss or reversal of impairment loss recognised in profit or loss for trade receivables. [Refer: Impairment loss recognised in profit or loss; Reversal of impairment loss recognised in profit or loss; Trade receivables] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The amount of expense recognised related to the write-down of inventories to net realisable value. [Refer: Inventories] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 2 -IssueDate 2020-01-01 -Paragraph 36 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=2&code=ifrs-tx-2020-en-r&anchor=para_36_e&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 98 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_98_a&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The amount of reversal of impairment loss recognised in profit or loss for investment property. [Refer: Reversal of impairment loss recognised in profit or loss; Investment property] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 40 -IssueDate 2020-01-01 -Paragraph 76 -Subparagraph g -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=40&code=ifrs-tx-2020-en-r&anchor=para_76_g&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 40 -IssueDate 2020-01-01 -Paragraph 79 -Subparagraph d -Clause v -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=40&code=ifrs-tx-2020-en-r&anchor=para_79_d_v&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The amount recognised resulting from the write-down of property, plant and equipment to its recoverable amount or reversals of those write-downs. [Refer: Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 98 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_98_a&doctype=Standard -URIDate 2020-01-01 + Details
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