| Component: (Network and Table) | |
|---|---|
| Network | 100690 - Disclosure - Geographic Information (Schedule of Revenues from External Customers by Geographical Areas) (Details) (http://www.powellind.com/20160930/taxonomy/role/DisclosureGeographicInformationScheduleOfRevenuesFromExternalCustomersByGeographicalAreasDetails) |
| Table | Schedule Of Revenues From External Customers And Long Lived Assets [Table] |
| Reporting Entity [Axis] | 0000080420 (http://www.sec.gov/CIK) |
| Revenues From External Customers And Long Lived Assets [Line Items] | Period [Axis] | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2015-10-01 - 2016-09-30 | 2014-10-01 - 2015-09-30 | 2013-10-01 - 2014-09-30 | |||||||||||||||||||
| Geographical | Geographical | Geographical | |||||||||||||||||||
| United States | Canada | Middle East and Africa | Europe | Far East | Mexico, Central and South America | Geographical | United States | Canada | Middle East and Africa | Europe | Far East | Mexico, Central and South America | Geographical | United States | Canada | Middle East and Africa | Europe | Far East | Mexico, Central and South America | Geographical | |
Total revenues | |||||||||||||||||||||