Geographic and Service Group Information (Geographic Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Jul. 03, 2015	Apr. 03, 2015	Dec. 30, 2016	Jan. 01, 2016	Jan. 02, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 62,946	$ 66,810	$ 68,178	$ 61,973	$ 60,261	$ 59,992	$ 59,423	$ 54,905	$ 288,561	$ 260,940	$ 236,737
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									246,249	218,719	190,050
International (Primarily European Countries) [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									$ 42,312	$ 42,221	$ 46,687