Subsequent Event	3 Months Ended
Mar. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent Event (Possible)On May [•], 2021, GP Strategies Corporation (the “Company”), a Delaware corporation, entered into an asset purchase agreement (the “Purchase Agreement”) with Toshiba America Energy Systems Corporation, a Delaware corporation (“Buyer”), pursuant to which the Company has agreed to sell substantially all of its assets and liabilities related to the EtaPRO business (the “Business”) to Buyer and certain of its affiliates (such contemplated sale, the “Transaction”). The aggregate purchase price for the Transaction is approximately $40 million in cash, subject to certain closing and post-closing purchase price adjustments set forth in the Purchase Agreement and an indemnity escrow of $4 million.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI http://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

Name:	us-gaap_SubsequentEventsTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration