Geographic and Service Group Information (Revenue By Service Group) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Dec. 29, 2017	Dec. 30, 2016	Jan. 01, 2016
Segment Reporting Information [Line Items]
Total revenue	$ 64,510	$ 65,947	$ 67,726	$ 65,069	$ 62,946	$ 66,810	$ 68,178	$ 61,973	$ 285,862	$ 288,561	$ 260,940
The Hackett Group [Member]
Segment Reporting Information [Line Items]
Total revenue									242,269	246,210	221,341
SAP/ERP Solutions [Member]
Segment Reporting Information [Line Items]
Total revenue									$ 43,593	$ 42,351	$ 39,599