Acquisitions - Business Acquisition Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Business Combinations [Abstract]
Net sales	$ 439,191	$ 405,573	$ 1,332,900	$ 1,171,283
Income before income taxes	71,737	50,883	228,503	102,429
Net income	$ 56,060	$ 40,004	$ 179,264	$ 95,047
Net income per share — basic (in dollars per share)	$ 2.23	$ 1.61	$ 7.17	$ 3.84
Net income per share — diluted (in dollars per share)	$ 2.18	$ 1.59	$ 7.16	$ 3.78