Retirement Benefit Plans - Principal Assumptions Used for Actuarial Valuations (Detail)	Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Defined Plan [line items]
Discount rates	1.00%	1.50%
Bottom of range [Member]
Disclosure Of Defined Plan [line items]
Expected rates of salary increase	1.20%	1.20%
Top of range [Member]
Disclosure Of Defined Plan [line items]
Expected rates of salary increase	2.00%	2.00%

The discount rate used as the significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit obligation, at present value; Actuarial assumptions [member]]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2018-01-01
-Paragraph 144
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2018-03-01&anchor=para_144&doctype=Standard
-URIDate 2018-03-16

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- Definition

The expected rate of salary increases used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit plans [member]; Defined benefit obligation, at present value; Actuarial assumptions [member]]

+ References

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- Definition

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.

+ References

No definition available.

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