Fair Value (Details) - USD ($)	Jan. 01, 2017	Jul. 03, 2016
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 0
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	1,451,607,000	$ 1,345,631,000
Fair Value, Measurements, Recurring [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	539,765,000	513,193,000
Fair Value, Measurements, Recurring [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	911,842,000	832,438,000
Fair Value, Measurements, Recurring [Member] | 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	539,765,000	513,193,000
Fair Value, Measurements, Recurring [Member] | 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	539,765,000	513,193,000
Fair Value, Measurements, Recurring [Member] | 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	911,842,000	832,438,000
Fair Value, Measurements, Recurring [Member] | 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	$ 911,842,000	$ 832,438,000