| Document and Entity Information | Oct. 29, 2019 |
| Cover [Abstract] | |
| Entity Registrant Name | TransDigm Group INC |
| Amendment Flag | false |
| Entity Central Index Key | 0001260221 |
| Document Type | 8-K |
| Document Period End Date | Oct. 29, 2019 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-32833 |
| 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $0.01 par value |
| Trading Symbol | TDG |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
