Revenue Classes - Schedule of Disaggregation of Revenue (Details) - KRW (₩) ₩ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Total	₩ 1,280,331	₩ 1,309,483	₩ 4,589,203	₩ 3,972,111
Products [Member] \| E- Navigation [Member]
Total	321,898	173,092	1,367,203	1,128,948
Products [Member] \| Smart Ship [Member]
Total	236,767	75,909	246,460	342,950
Projects [Member] \| E- Navigation [Member]
Total	721,665	931,992	1,889,183	1,734,111
Projects [Member] \| Smart Ship [Member]
Total		₩ 128,489	₩ 1,086,358	₩ 766,102

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration