Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 12, 2021	Jun. 30, 2020
Cover [Abstract]
Entity Registrant Name	POWER SOLUTIONS INTERNATIONAL, INC.
Entity Central Index Key	0001137091
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Transition Report	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		22,892,413
Entity Interactive Data Current	Yes
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Public Float			$ 20,631,024