Cover Page - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Feb. 25, 2021	Jun. 30, 2020
Cover [Abstract]
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0000070415
Current Fiscal Year End Date	--12-31
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	1-7234
Entity Registrant Name	GP STRATEGIES CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	52-0845774
Entity Address, Address Line One	70 Corporate Center
Entity Address, Address Line Two	11000 Broken Land Parkway, Suite 300,
Entity Address, City or Town	Columbia
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	21044
City Area Code	(443)
Local Phone Number	367-9600
Title of 12(b) Security	Common Stock, $.01 par value
Trading Symbol	GPX
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 109,684
Entity Common Stock, Shares Outstanding		17,349,122