Cash, Cash Equivalents, and Investments - Summary of Available-for-Sale Investments (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 28, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 456,130
Gross Unrealized Gains	1,183
Gross Unrealized Losses	(228)
Fair Value	457,085
Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Losses	(144)
Corporate Bonds | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	45,785
Gross Unrealized Gains	106
Gross Unrealized Losses	(2)
Fair Value	45,889
Corporate Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	208,585
Gross Unrealized Gains	936
Gross Unrealized Losses	(142)
Fair Value	209,379
Municipal Bonds | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,970
Gross Unrealized Gains	1
Gross Unrealized Losses	0
Fair Value	1,971
Municipal Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,989
Gross Unrealized Gains	54
Gross Unrealized Losses	0
Fair Value	7,043
Sovereign Bonds
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Losses	(12)
Sovereign Bonds | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,704
Gross Unrealized Gains	5
Gross Unrealized Losses	0
Fair Value	1,709
Sovereign Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	17,516
Gross Unrealized Gains	21
Gross Unrealized Losses	(12)
Fair Value	17,525
Asset-Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Losses	(37)
Asset-Backed Securities | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	189
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	189
Asset-Backed Securities | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	64,936
Gross Unrealized Gains	42
Gross Unrealized Losses	(37)
Fair Value	64,941
Treasury Bills
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Losses	(29)
Treasury Bills | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	102,685
Gross Unrealized Gains	18
Gross Unrealized Losses	(29)
Fair Value	102,674
Agency Bonds
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Losses	(6)
Agency Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,771
Gross Unrealized Gains	0
Gross Unrealized Losses	(6)
Fair Value	$ 5,765