Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2017	Sep. 27, 2016	Oct. 03, 2017	Sep. 27, 2016
Net Income Per Share
Antidilutive securities excluded from calculation of basic earnings per share (in shares)			1,300	1,400
Net income per share, basic and diluted
Net income	$ 26,445	$ 34,574	$ 99,654	$ 107,113
Basic weighted average shares outstanding (in shares)	46,602	47,815	47,323	48,188
Dilutive effect of equity awards (in shares)	917	1,397	1,259	1,416
Diluted weighted average shares outstanding (in shares)	47,519	49,212	48,582	49,604
Basic net income per share (in dollars per share)	$ 0.57	$ 0.72	$ 2.11	$ 2.22
Diluted net income per share (in dollars per share)	$ 0.56	$ 0.70	$ 2.05	$ 2.16