Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 22, 2020
Document And Entity Information [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-Q
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		22,857,602
Entity Current Reporting Status	No
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Interactive Data Current	Yes