Document And Entity Information	6 Months Ended
	Dec. 31, 2011	Feb. 08, 2012
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Dec. 31, 2011
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2012
Entity Registrant Name	PERCEPTRON INC/MI
Entity Central Index Key	0000887226
Current Fiscal Year End Date	--06-30
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		8,395,335