Contingent Consideration (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Contingent Consideration [Abstract]
Contingent consideration accrued, current	$ 0	$ 1,701

Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled within one year or the normal operating cycle, if longer.

No definition available.

Name:	gvp_CurrentContingentConsideration
Namespace Prefix:	gvp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant