Investments (Contractual Maturities of Marketable Investments) (Details) - USD ($) $ in Thousands	Jun. 25, 2017	Jun. 26, 2016
Schedule of Available-for-sale Securities [Line Items]
Within One Year	$ 99,989
After One, Within Five Years	317,208
After Five, Within Ten Years	61,144
After Ten Years	0
Total	478,341	$ 439,151
Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Within One Year	45,519
After One, Within Five Years	107,947
After Five, Within Ten Years	26,575
After Ten Years	0
Total	180,041	190,440
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Within One Year	48,515
After One, Within Five Years	94,637
After Five, Within Ten Years	34,569
After Ten Years	0
Total	177,721	168,767
Non-U.S. certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Within One Year	5,755
After One, Within Five Years	114,624
After Five, Within Ten Years	0
After Ten Years	0
Total	120,379	73,127
U.S. certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Within One Year	0
After One, Within Five Years	0
After Five, Within Ten Years	0
After Ten Years	0
Total	0	3,500
Commercial Paper
Schedule of Available-for-sale Securities [Line Items]
Within One Year	200
After One, Within Five Years	0
After Five, Within Ten Years	0
After Ten Years	0
Fair Value, Measurements, Recurring [Member]
Schedule of Available-for-sale Securities [Line Items]
Total	478,341	439,151
Fair Value, Measurements, Recurring [Member] | Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Total	180,041	190,440
Fair Value, Measurements, Recurring [Member] | Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Total	177,721	168,767
Fair Value, Measurements, Recurring [Member] | Non-U.S. certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Total	120,379	73,127
Fair Value, Measurements, Recurring [Member] | U.S. certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Total	0	3,500
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Total	478,341	439,151
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Total	180,041	190,440
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Total	177,721	168,767
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Non-U.S. certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Total	120,379	73,127
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Total	$ 0	$ 3,500