Document and Entity Information - USD ($)	6 Months Ended
	Jun. 30, 2015	Aug. 13, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	GSE SYSTEMS INC
Entity Central Index Key	0000944480
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Smaller Reporting Company
Entity Public Float	$ 27,315,219
Entity Common Stock, Shares Outstanding		17,887,859
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2015