Cover Page - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2021	Nov. 30, 2021	Mar. 31, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Sep. 30, 2021
Current Fiscal Year End Date	--09-30
Document Transition Report	false
Entity File Number	1-31923
Entity Registrant Name	UNIVERSAL TECHNICAL INSTITUTE, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	86-0226984
Entity Address, Address Line One	4225 East Windrose Drive
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	Phoenix
Entity Address, State or Province	AZ
Entity Address, Postal Zip Code	85032
City Area Code	623
Local Phone Number	445-9500
Title of 12(b) Security	Common Stock, $0.0001 par value
Trading Symbol	UTI
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 Common Stock, Shares Outstanding		32,832,555
Entity Public Float			$ 186
Documents Incorporated by Reference	Portions of the registrant's definitive proxy statement for the 2022 Annual Meeting of Stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K.
Entity Central Index Key	0001261654
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false