Cash, Cash Equivalents, and Investments - Summary of Available-for-Sale Investments (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 408,858
Gross Unrealized Gains	986
Gross Unrealized Losses	(871)
Fair Value	408,973
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	210,341
Corporate Bonds [Member] | Short-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	104,580
Gross Unrealized Gains	270
Gross Unrealized Losses	(130)
Fair Value	104,720
Corporate Bonds [Member] | Long-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	105,251
Gross Unrealized Gains	513
Gross Unrealized Losses	(143)
Fair Value	105,621
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	69,928
Asset-Backed Securities [Member] | Short-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	41,600
Gross Unrealized Gains	7
Gross Unrealized Losses	(338)
Fair Value	41,269
Asset-Backed Securities [Member] | Long-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	28,810
Gross Unrealized Gains	10
Gross Unrealized Losses	(161)
Fair Value	28,659
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	28,005
Municipal Bonds [Member] | Short-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	16,969
Gross Unrealized Gains	44
Fair Value	17,013
Municipal Bonds [Member] | Long-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,957
Gross Unrealized Gains	45
Gross Unrealized Losses	(10)
Fair Value	10,992
Treasury Bills [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	69,277
Treasury Bills [Member] | Short-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,647
Gross Unrealized Gains	7
Fair Value	11,654
Treasury Bills [Member] | Long-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	57,604
Gross Unrealized Gains	24
Gross Unrealized Losses	(5)
Fair Value	57,623
Sovereign Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	29,923
Sovereign Bonds [Member] | Short-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	8,554
Gross Unrealized Gains	9
Gross Unrealized Losses	(10)
Fair Value	8,553
Sovereign Bonds [Member] | Long-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	21,386
Gross Unrealized Gains	57
Gross Unrealized Losses	(73)
Fair Value	21,370
Agency Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	1,499
Agency Bonds [Member] | Short-Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,500
Gross Unrealized Losses	(1)
Fair Value	$ 1,499