Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 02, 2018	Oct. 03, 2017	Oct. 02, 2018	Oct. 03, 2017
Net Income Per Share
Antidilutive securities excluded from calculation of basic earnings per share (in shares)			1,300	1,300
Net income per share, basic and diluted
Net income	$ 28,475	$ 26,445	$ 82,857	$ 99,654
Basic weighted average shares outstanding (in shares)	45,321	46,602	45,418	47,323
Dilutive effect of equity awards (in shares)	1,047	917	982	1,259
Diluted weighted average shares outstanding (in shares)	46,368	47,519	46,400	48,582
Basic net income per share (in dollars per share)	$ 0.63	$ 0.57	$ 1.82	$ 2.11
Diluted net income per share (in dollars per share)	$ 0.61	$ 0.56	$ 1.79	$ 2.05
Restricted Shares and Restricted Share Units
Net Income Per Share
Antidilutive securities excluded from calculation of basic earnings per share (in shares)			1,700	1,800