Fair Value Information - Additional Information (Detail) - TWD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Fair Value Measurement Of Financial Instruments [Abstract]
Transfer between Level 1 and 2, assets	$ 0	$ 0
Transfer between Level 2 and 1, assets	0	0
Transfer between Level 1 and 2, liabilities	0	0
Transfer between Level 2 and 1, liabilities	$ 0	$ 0

Disclosure of fair value measurement of financial instruments.

No definition available.

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- Definition

The amount of transfers out of Level 1 and into Level 2 of the fair value hierarchy of assets held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 13
-IssueDate 2018-01-01
-Paragraph 93
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=13&date=2018-03-01&anchor=para_93_c&doctype=Standard
-URIDate 2018-03-16

+ Details

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- Definition

The amount of transfers out of Level 1 and into Level 2 of the fair value hierarchy of liabilities held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]

+ References

+ Details

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- Definition

The amount of transfers out of Level 2 and into Level 1 of the fair value hierarchy of assets held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]

+ References

+ Details

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- Definition

The amount of transfers out of Level 2 and into Level 1 of the fair value hierarchy of liabilities held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]

+ References

+ Details

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