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Marketable Securities (Details) - USD ($)
$ in Thousands
6 Months Ended
Jun. 26, 2016
Dec. 27, 2015
Debt Securities    
Schedule of Held-to-maturity Securities [Line Items]    
Short-term marketable securities $ 327,641 $ 507,639
Long-term marketable securities 187,679 291,136
Debt Securities | US Treasury Securities    
Schedule of Held-to-maturity Securities [Line Items]    
Short-term marketable securities 85,451 184,278
Long-term marketable securities 17,783 20,769
Debt Securities | Corporate Debt Securities    
Schedule of Held-to-maturity Securities [Line Items]    
Short-term marketable securities 141,425 185,561
Long-term marketable securities 81,358 119,784
Debt Securities | US Agency Securities    
Schedule of Held-to-maturity Securities [Line Items]    
Short-term marketable securities 53,649 65,222
Long-term marketable securities 88,538 150,583
Debt Securities | Municipal Securities    
Schedule of Held-to-maturity Securities [Line Items]    
Short-term marketable securities 0 1,363
Debt Securities | Certificates of Deposit    
Schedule of Held-to-maturity Securities [Line Items]    
Short-term marketable securities 28,246 60,244
Debt Securities | Commercial Paper    
Schedule of Held-to-maturity Securities [Line Items]    
Short-term marketable securities $ 18,870 $ 10,971
Short-term Marketable Securities | Minimum    
Schedule of Held-to-maturity Securities [Line Items]    
Term of investments 1 month  
Short-term Marketable Securities | Maximum    
Schedule of Held-to-maturity Securities [Line Items]    
Term of investments 12 months  
Long-term Marketable Securities | Minimum    
Schedule of Held-to-maturity Securities [Line Items]    
Term of investments 13 months  
Long-term Marketable Securities | Maximum    
Schedule of Held-to-maturity Securities [Line Items]    
Term of investments 29 months