Cover	Feb. 16, 2022
Cover [Abstract]
Document Type	8-K
Document Period End Date	Feb. 16, 2022
Entity Registrant Name	POWELL INDUSTRIES, INC.
Entity Incorporation, State or Country Code	DE
Entity File Number	001-12488
Entity Tax Identification Number	88-0106100
Entity Address, Address Line One	8550 Mosley Road
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77075-1180
City Area Code	713
Local Phone Number	944-6900
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	POWL
Security Exchange Name	NASDAQ
Entity Emerging Growth Company	false
Amendment Flag	false
Entity Central Index Key	0000080420