Document And Entity Information (USD $)	9 Months Ended
	Sep. 30, 2012
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	No
Entity Filer Category	Smaller Reporting Company
Entity Public Float	$ 41,250,576
Entity Common Stock, Shares Outstanding	19,388,892
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2012