Document and Entity Information - shares	6 Months Ended
	Jul. 04, 2015	Jul. 30, 2015
Document and Entity Information
Entity Registrant Name	CRA INTERNATIONAL, INC.
Entity Central Index Key	0001053706
Document Type	10-Q
Document Period End Date	Jul. 04, 2015
Amendment Flag	false
Current Fiscal Year End Date	--01-02
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		9,069,586
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2