Cash Equivalents and Investments - Gross Unrealized Losses and Fair Values of Company's Short-Term Investments (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous unrealized loss position, Less than 12 Months, Fair Value	$ 111,841	$ 56,581
Available-for-sale Securities, Continuous unrealized loss position, Less than 12 Months, Unrealized Losses	(2,391)	(1,024)
Available-for-sale Securities, Continuous unrealized loss position, Greater than 12 Months, Fair Value	6,499	4,141
Available-for-sale Securities, Continuous unrealized loss position, Greater than 12 Months, Unrealized Losses	(217)	(79)
Asset-backed and mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous unrealized loss position, Less than 12 Months, Fair Value	70,172	38,280
Available-for-sale Securities, Continuous unrealized loss position, Less than 12 Months, Unrealized Losses	(2,040)	(1,018)
Available-for-sale Securities, Continuous unrealized loss position, Greater than 12 Months, Fair Value	6,499	4,141
Available-for-sale Securities, Continuous unrealized loss position, Greater than 12 Months, Unrealized Losses	(217)	(79)
Government and agency securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous unrealized loss position, Less than 12 Months, Fair Value	32,035	18,301
Available-for-sale Securities, Continuous unrealized loss position, Less than 12 Months, Unrealized Losses	(305)	(6)
Available-for-sale Securities, Continuous unrealized loss position, Greater than 12 Months, Fair Value
Available-for-sale Securities, Continuous unrealized loss position, Greater than 12 Months, Unrealized Losses
Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous unrealized loss position, Less than 12 Months, Fair Value	9,634
Available-for-sale Securities, Continuous unrealized loss position, Less than 12 Months, Unrealized Losses	(46)
Available-for-sale Securities, Continuous unrealized loss position, Greater than 12 Months, Fair Value
Available-for-sale Securities, Continuous unrealized loss position, Greater than 12 Months, Unrealized Losses