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Share-based Payments Arrangement - Black-Scholes Model and Related Assumptions used to Evaluate Options and Fair Value of Options by CHPT (Detail)	Oct. 31, 2018 TWD ($) yr $ / shares	May 22, 2018 TWD ($) d $ / shares	Dec. 19, 2017 TWD ($) yr $ / shares	Sep. 18, 2017 TWD ($) d $ / shares	Mar. 10, 2016 TWD ($) d $ / shares	Oct. 22, 2015 TWD ($) yr $ / shares
CHIEF Telecom Inc. (CHIEF) [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Grant-date share price | $ / shares	$ 166.00	$ 156.41	$ 95.92			$ 39.55
Exercise price	$ 147.00	$ 170.00	$ 147.00			$ 43.00
Dividends yield	0.00%	0.00%	0.00%			0.00%
Risk-free interest rate	0.72%	0.34%	0.62%			0.86%
Expected life	5	7	5			5
Expected volatility	16.60%	14.33%	17.35%			21.02%
Weighted average fair value of grants	$ 33,540	$ 0	$ 2,318			$ 4,863
Chunghwa Precision Test Tech. Co., Ltd. (CHPT) [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Grant-date share price | $ / shares				$ 1,295.00	$ 302.46
Exercise price				$ 1,267.33	$ 360.00
Dividends yield				0.00%	0.00%
Risk-free interest rate				0.35%	0.37%
Expected life | d				4	12
Expected volatility				28.30%	37.43%
Weighted average fair value of grants				$ 31.60	$ 0.04

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- Definition

Share price per share.

+ References

No definition available.

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- Definition

The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time.

+ References

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- Definition

The option life of share options granted.

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The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]]

+ References

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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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The exercise price of share options granted.

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The percentage of an expected dividend used to calculate the fair value of share options granted.

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The weighted average fair value of share options granted during the period at the measurement date. [Refer: Weighted average [member]]

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