Document and Entity Information - shares	3 Months Ended
	Sep. 30, 2016	Oct. 17, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	TRC COMPANIES INC /DE/
Entity Central Index Key	0000103096
Current Fiscal Year End Date	--06-30
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		31,390,002