| Document and Entity Information | Aug. 11, 2021 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001137091 |
| Document Type | 8-K |
| Document Period End Date | Aug. 11, 2021 |
| Entity Registrant Name | Power Solutions International, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-35944 |
| Entity Tax Identification Number | 33-0963637 |
| Entity Address, Address Line One | 201 Mittel Drive |
| Entity Address, City or Town | Wood Dale |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 60191 |
| City Area Code | (630) |
| Local Phone Number | 350-9400 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
