Cover Page Cover Page - shares	3 Months Ended
	Dec. 28, 2019	Jan. 26, 2020
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Dec. 28, 2019
Document Transition Report	false
Entity File Number	001-32833
Entity Registrant Name	TransDigm Group Incorporated
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	41-2101738
Entity Address, Address Line One	1301 East 9th Street,
Entity Address, Address Line Two	Suite 3000,
Entity Address, City or Town	Cleveland,
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	44114
City Area Code	216
Local Phone Number	706-2960
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	TDG
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		53,667,940
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001260221
Document Fiscal Year Focus	2020
Amendment Flag	false
Current Fiscal Year End Date	--09-30