Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 30, 2016
Consolidated Balance Sheets [Abstract]
Accounts receivable and unbilled revenue, allowance	$ 2,249	$ 2,574
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	1,250,000	1,250,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	55,446,676	54,785,193
Treasury stock, at cost, shares	26,256,909	26,197,981