Fair Value Measurements - Maturity Dates of Investments (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 29, 2014	Dec. 31, 2013
Fair Value Measurements, Maturity Dates Of Investments [Line Items]
Amortized Cost	$ 416,676	$ 353,109
Estimated Fair Value	416,731	352,968
Less Than 1 Year [Member]
Fair Value Measurements, Maturity Dates Of Investments [Line Items]
Amortized Cost	113,737
Estimated Fair Value	113,835
1 to 5 Years [Member]
Fair Value Measurements, Maturity Dates Of Investments [Line Items]
Amortized Cost	294,039
Estimated Fair Value	294,435
6 to 10 Years [Member]
Fair Value Measurements, Maturity Dates Of Investments [Line Items]
Amortized Cost	8,900
Estimated Fair Value	8,461
Thereafter [Member]
Fair Value Measurements, Maturity Dates Of Investments [Line Items]
Amortized Cost	0
Estimated Fair Value	$ 0