Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 27, 2020
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Trading Symbol	GTX
Entity Registrant Name	Garrett Motion Inc.
Entity Central Index Key	0001735707
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		75,635,938
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-38636
Entity Tax Identification Number	82-4873189
Entity Address, Address Line One	La Pièce 16
Entity Address, City or Town	Rolle
Entity Incorporation, State or Country Code	DE
Entity Address, Country	CH
Entity Address, Postal Zip Code	1180
City Area Code	41 21
Local Phone Number	695 30 00
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock,$0.001 par value per share
Security Exchange Name	NYSE
Document Quarterly Report	true
Document Transition Report	false