Intangible Assets - Schedule of Intangible Assets (Details) - KRW (₩) ₩ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Gross Carrying Amount	₩ 590,763	₩ 590,762
Accumulated Amortization	(313,758)	(288,607)
Net Carrying Amount	277,005	302,155
Industrial Property Rights [Member]
Gross Carrying Amount	5,960	5,960
Accumulated Amortization	(5,331)	(5,260)
Net Carrying Amount	629	700
Software [Member]
Gross Carrying Amount	62,782	62,782
Accumulated Amortization	(62,782)	(62,782)
Net Carrying Amount		0
Customers Relationship [Member]
Gross Carrying Amount	500,000	500,000
Accumulated Amortization	(225,000)	(200,000)
Net Carrying Amount	275,000	300,000
Other [Member]
Gross Carrying Amount	22,021	22,020
Accumulated Amortization	(20,645)	(20,565)
Net Carrying Amount	₩ 1,376	₩ 1,455