Operations in Different Geographic Areas (Detail) - 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
Operations in Different Geographic Areas [Line Items]
Property, Equipment and Leasehold Improvements, net		$ 36,710				$ 28,485				$ 36,710		$ 28,485
Revenues		77,013	$ 77,612	$ 77,295	$ 83,156	73,681	$ 78,994	$ 79,864	$ 80,293	315,076	[1]	312,832	[1]	$ 304,704	[1]
United States
Operations in Different Geographic Areas [Line Items]
Property, Equipment and Leasehold Improvements, net		35,746				27,775				35,746		27,775
Revenues	[1]									281,223		281,618		273,635
Foreign Countries
Operations in Different Geographic Areas [Line Items]
Property, Equipment and Leasehold Improvements, net		$ 964				$ 710				964		710
Revenues	[1]									$ 33,853		$ 31,214		$ 31,069

[1] Geographic revenues are allocated based on the location of the client.