Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 191,445		$ 192,879
Less: Accumulated depreciation and amortization	(96,170)		(86,593)
Property and equipment, net	95,275		106,286
Depreciation and amortization expense	13,400	$ 10,500
Tooling and manufacturing equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	80,200		80,685
Furniture and office equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	22,454		22,738
Purchased and internally-developed software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	24,200		21,741
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 64,591		$ 67,715