Segment Information - Revenues and Long-lived Assets by Geographical Area (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 30, 2017
Segment Reporting Information [Line Items]
Net sales	$ 439,191	$ 317,889	$ 1,316,187	$ 916,685
Long-lived assets	343,883		343,883		$ 250,577
Additions to long-lived assets			55,946	48,470
United States
Segment Reporting Information [Line Items]
Net sales	125,867	103,233	386,980	290,538
Long-lived assets	66,098		66,098		23,490
Additions to long-lived assets			5,636	2,752
China
Segment Reporting Information [Line Items]
Net sales	117,813	82,986	352,097	240,731
Long-lived assets	89,856		89,856		86,866
Additions to long-lived assets			19,043	22,165
Mexico
Segment Reporting Information [Line Items]
Long-lived assets	69,395		69,395		62,510
Additions to long-lived assets			14,089	15,041
Germany
Segment Reporting Information [Line Items]
Long-lived assets	37,281		37,281		1,082
Additions to long-lived assets			5,917	67
Philippines
Segment Reporting Information [Line Items]
Long-lived assets	31,589		31,589		31,129
Additions to long-lived assets			6,133	2,018
Other countries
Segment Reporting Information [Line Items]
Net sales	195,511	$ 131,670	577,110	385,416
Long-lived assets	$ 49,664		49,664		$ 45,500
Additions to long-lived assets			$ 5,128	$ 6,427