Consolidated Statements of Net Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Net sales	$ 1,221,534	$ 1,056,159	$ 867,864
Cost of sales	715,001	643,042	537,365
Gross profit	506,533	413,117	330,499
Selling, general, and administrative expenses	212,833	206,129	153,714
Research and development expenses	50,489	42,198	30,802
Pension settlement expenses			29,928
Amortization of intangibles	24,700	19,337	11,898
Impairment of goodwill and intangible assets		14,809
Total operating expenses	288,022	282,473	226,342
Operating income	218,511	130,644	104,157
Interest expense	13,380	8,628	4,091
Foreign exchange loss (gain)	2,376	472	(1,465)
Other (income) expense, net	(1,282)	(1,730)	(5,417)
Income before income taxes	204,037	123,274	106,948
Income taxes	84,518	18,786	26,082
Net income	$ 119,519	$ 104,488	$ 80,866
Income per share:
Basic (in dollars per share)	$ 5.27	$ 4.63	$ 3.58
Diluted (in dollars per share)	$ 5.21	$ 4.60	$ 3.56
Weighted-average shares and equivalent shares outstanding:
Basic (in shares)	22,687	22,559	22,565
Diluted (in shares)	22,931	22,727	22,719