Cash, Cash Equivalents, and Investments - Summary of Available-for-Sale Investments (Detail) $ in Thousands	Oct. 01, 2017 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 658,638
Gross unrealized gains	1,612
Gross unrealized losses	(488)
Fair value	659,762
Treasury Bills
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	(229)
Treasury Bills | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	70,311
Gross unrealized gains	0
Gross unrealized losses	(127)
Fair value	70,184
Treasury Bills | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	63,704
Gross unrealized gains	0
Gross unrealized losses	(102)
Fair value	63,602
Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	(125)
Corporate Bonds | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	65,484
Gross unrealized gains	91
Gross unrealized losses	(6)
Fair value	65,569
Corporate Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	245,046
Gross unrealized gains	1,013
Gross unrealized losses	(119)
Fair value	245,940
Euro Liquidity Fund | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	51,929
Gross unrealized gains	383
Gross unrealized losses	0
Fair value	52,312
Asset-Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	(57)
Asset-Backed Securities | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	47,839
Gross unrealized gains	13
Gross unrealized losses	(12)
Fair value	47,840
Asset-Backed Securities | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	59,038
Gross unrealized gains	76
Gross unrealized losses	(45)
Fair value	59,069
Sovereign Bonds
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	(74)
Sovereign Bonds | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	20,974
Gross unrealized gains	5
Gross unrealized losses	(34)
Fair value	20,945
Sovereign Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	8,059
Gross unrealized gains	7
Gross unrealized losses	(40)
Fair value	8,026
Agency Bonds | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	7,600
Gross unrealized gains	6
Gross unrealized losses	0
Fair value	7,606
Agency Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	5,630
Gross unrealized gains	9
Gross unrealized losses	0
Fair value	5,639
Municipal Bonds
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	(3)
Municipal Bonds | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	8,805
Gross unrealized gains	0
Gross unrealized losses	0
Fair value	8,805
Municipal Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	4,219
Gross unrealized gains	9
Gross unrealized losses	(3)
Fair value	$ 4,225