Subsidiaries - Summary of Net Cash Inflow on Acquisition of Subsidiaries (Detail) - IISI and its Subsidiaries [Member] $ in Millions	Jul. 01, 2020 TWD ($)
Disclosure Of Business Combinations [Line Items]
Cash and cash equivalents acquired	$ 588
Less: Consideration paid in cash	(234)
Net cash inflow on acquisition of subsidiaries	$ 354

The amount recognised as of the acquisition date for cash and cash equivalents acquired in a business combination. [Refer: Cash and cash equivalents; Business combinations [member]]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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The aggregate cash flows arising from losing control of subsidiaries or other businesses, classified as investing activities. [Refer: Subsidiaries [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
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-IssueDate 2022-03-24
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The fair value, at acquisition date, of cash transferred as consideration in a business combination. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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