Pension Plans - Schedule of Components of Benefit Expense (Details) - KRW (₩) ₩ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Service cost	₩ 205,742	₩ 226,787
Interest cost	11,175	10,991
Prior service cost
Total	₩ 216,916	₩ 237,779

No definition available.

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Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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Amount of noncash expense (reversal of expense) for pension and other postretirement benefits.

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