Acquisition - Pro Forma Information Adjustments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net income	$ 56,060	$ 40,004	$ 179,264	$ 95,047
Amortization
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net income	3,104	(6,304)	8,289	(18,905)
Depreciation
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net income	0	139	0	417
Transaction costs
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net income	0	0	9,976	(9,976)
Amortization of inventory step-up
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net income	0	0	36,927	(36,927)
Stock compensation
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net income	421	(426)	5,110	(6,206)
Interest expense
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net income	0	(2,582)	0	(7,746)
Income tax impact of above items
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Net income	$ (1,011)	$ 2,906	$ (14,290)	$ 25,802