Fair Value Measurements - Maturity Dates of Investments (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 27, 2014	Dec. 31, 2013
Fair Value Measurements, Maturity Dates Of Investments [Line Items]
Amortized Cost	$ 480,807	$ 353,109
Estimated Fair Value	481,706	352,968
Less Than 1 Year [Member]
Fair Value Measurements, Maturity Dates Of Investments [Line Items]
Amortized Cost	135,482
Estimated Fair Value	135,603
1 to 5 Years [Member]
Fair Value Measurements, Maturity Dates Of Investments [Line Items]
Amortized Cost	342,925
Estimated Fair Value	343,703
6 to 10 Years [Member]
Fair Value Measurements, Maturity Dates Of Investments [Line Items]
Amortized Cost	2,400
Estimated Fair Value	2,400
Thereafter [Member]
Fair Value Measurements, Maturity Dates Of Investments [Line Items]
Amortized Cost	0
Estimated Fair Value	$ 0