Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Numerator:
Net income as reported	$ 53,546	$ 42,808	$ 131,900	$ 130,338
Weighted average shares outstanding
Basic (in shares)	25,109	22,713	24,817	22,678
Effect of dilutive securities (in shares)	362	240	395	228
Diluted (in shares)	25,471	22,953	25,212	22,906
Earnings Per Share:
Basic earnings per share (in dollars per share)	$ 2.13	$ 1.88	$ 5.31	$ 5.75
Diluted earnings per share (in dollars per share)	$ 2.10	$ 1.87	$ 5.23	$ 5.69