Document And Entity Information (USD $)	12 Months Ended
	Jun. 30, 2012	Sep. 20, 2012	Dec. 31, 2011
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jun. 30, 2012
Document Fiscal Period Focus	FY
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		8,455,465
Entity Current Reporting Status	No
Entity Public Float			$ 37,700,000
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	Yes