Property and Equipment (Details) (USD $)	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Property and equipment
Property and equipment, gross	$ 54,210,000	$ 53,375,000
Accumulated depreciation and amortization	(38,555,000)	(35,395,000)
Property and equipment, net	15,655,000	17,980,000
Depreciation expense, including amounts recorded in costs of services	5,200,000	5,000,000	4,100,000
Computer, office equipment and software
Property and equipment
Property and equipment, gross	25,034,000	24,867,000
Leasehold improvements
Property and equipment
Property and equipment, gross	21,388,000	20,622,000
Furniture
Property and equipment
Property and equipment, gross	$ 7,788,000	$ 7,886,000