Cash, Cash Equivalents, and Investments - Components of Cash, Cash Equivalents, and Investments (Detail) - USD ($) $ in Thousands	Apr. 02, 2017	Dec. 31, 2016	Apr. 03, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Cash	$ 88,533	$ 77,307
Money market instruments	3,895	2,334
Cash and cash equivalents	92,428	79,641	$ 79,914	$ 51,975
Short-term investments	376,027	341,194
Long-term investments	312,850	324,335
Total	781,305	745,170
Treasury Bills
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	92,883	67,175
Long-term investments	53,370	92,280
Euro Liquidity Fund
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	73,868	46,499
Asset-Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	58,649	69,614
Long-term investments	43,047	26,946
Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	128,507	141,188
Long-term investments	195,128	169,952
Agency Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	7,620	2,903
Long-term investments	2,728	10,339
Sovereign Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	12,340	7,298
Long-term investments	18,577	23,585
Municipal Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	2,160	6,517
Long-term investments	$ 0	$ 1,233