Inventories - Summary of Inventories (Detail) $ in Millions, $ in Millions	Jun. 30, 2021 TWD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 TWD ($)
Classes of current inventories [abstract]
Finished goods	$ 21,358.6		$ 21,705.6
Work in process	126,550.9		91,672.9
Raw materials	12,991.5		14,716.0
Supplies and spare parts	9,537.7		9,258.9
Inventories, total	$ 170,438.7	$ 6,106.7	$ 137,353.4

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A classification of current inventory representing the amount of goods that have completed the production process and are held for sale in the ordinary course of business. [Refer: Inventories]

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The amount of current inventories. [Refer: Inventories]

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A classification of current inventory representing the amount of assets to be consumed in the production process or in the rendering of services. [Refer: Inventories]

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A classification of current inventory representing the amount of interchangeable parts that are kept in an inventory and are used for the repair or replacement of failed parts. [Refer: Inventories]

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A classification of current inventory representing the amount of assets currently in production, which require further processes to be converted into finished goods or services. [Refer: Current finished goods; Inventories]

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