Geographic and Group Information (Revenue By Service Group) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Revenue before reimbursements	$ 75,649	$ 73,570	$ 148,382	$ 144,999
Revenue Before Reimbursements [Member]
Segment Reporting Information [Line Items]
Revenue before reimbursements	69,614	67,726	137,089	132,795
The Hackett Group [Member] | Revenue Before Reimbursements [Member]
Segment Reporting Information [Line Items]
Revenue before reimbursements	61,287	57,658	120,185	112,649
SAP Solutions [Member] | Revenue Before Reimbursements [Member]
Segment Reporting Information [Line Items]
Revenue before reimbursements	$ 8,327	$ 10,068	$ 16,904	$ 20,146