CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 30, 2017
CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited)
Allowances for accounts receivable (in dollars)	$ 6,912	$ 7,378
Allowance for unbilled services (in dollars)	$ 2,659	$ 1,746
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value ( in dollars per share )	$ 0	$ 0
Common stock, shares authorized	25,000,000	25,000,000
Common stock, shares issued	8,221,403	8,297,172
Common stock, shares outstanding	8,221,403	8,297,172