Fair Value (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Dec. 28, 2014	Jun. 29, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 1,013,183	$ 890,566
U.S. Treasury Securities and Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	446,571	443,635
Municipal Bonds, U.S. Government-Sponsored Enterprises and Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	566,612	446,931
Quoted Prices in Active Markets for Identical Instruments (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	446,571	443,635
Quoted Prices in Active Markets for Identical Instruments (Level 1) [Member] | U.S. Treasury Securities and Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	446,571	443,635
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	566,612	446,931
Significant Other Observable Inputs (Level 2) [Member] | Municipal Bonds, U.S. Government-Sponsored Enterprises and Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 566,612	$ 446,931