| Cover | Feb. 16, 2023 | Feb. 15, 2023 |
| Cover [Abstract] | ||
| Document Type | 8-K | |
| Document Period End Date | Feb. 15, 2023 | |
| 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 |
