Geographical Information - Revenue by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	$ 290,213	$ 228,261	$ 605,055	$ 432,855
United States [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	159,187	129,349	343,962	233,705
China [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	16,812	5,166	18,978	18,113
Singapore [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	82,904	73,810	185,537	134,050
Austria [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	16,393	8,491	29,929	19,712
Other [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	$ 14,917	$ 11,445	$ 26,649	$ 27,275