Fair Value of Financial Instruments - Summary (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jun. 24, 2018
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	$ 238.1	$ 77.8
Total short-term investments	550.9	268.2
Common stock of non-U.S. corporations	39.5	57.5
Total assets	828.5	403.5
Municipal bonds
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	78.5	109.3
Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	257.0	76.8
U.S. agency securities
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	25.6	3.9
U.S. treasury securities
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	92.5	0.0
Certificates of deposit | United States
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	22.4	0.5
Certificates of deposit | Non-US
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	50.2	77.7
Commercial paper
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	7.8	0.0
Variable rate demand note
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	16.9	0.0
Money market funds
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	95.0	42.9
Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	15.0	0.0
U.S. agency securities
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	18.8	0.0
U.S. treasury securities
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	2.5	0.0
Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	105.8	34.6
Commercial paper
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	1.0	0.3
Level 1
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	97.5	42.9
Total short-term investments	92.5	3.9
Common stock of non-U.S. corporations	0.0	0.0
Total assets	190.0	46.8
Level 1 | Municipal bonds
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 1 | Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 1 | U.S. agency securities
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	3.9
Level 1 | U.S. treasury securities
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	92.5	0.0
Level 1 | Certificates of deposit | United States
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 1 | Certificates of deposit | Non-US
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 1 | Commercial paper
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 1 | Variable rate demand note
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 1 | Money market funds
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	95.0	42.9
Level 1 | Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Level 1 | U.S. agency securities
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Level 1 | U.S. treasury securities
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	2.5	0.0
Level 1 | Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Level 1 | Commercial paper
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Level 2
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	140.6	34.9
Total short-term investments	458.4	264.3
Common stock of non-U.S. corporations	39.5	57.5
Total assets	638.5	356.7
Level 2 | Municipal bonds
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	78.5	109.3
Level 2 | Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	257.0	76.8
Level 2 | U.S. agency securities
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	25.6	0.0
Level 2 | U.S. treasury securities
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 2 | Certificates of deposit | United States
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	22.4	0.5
Level 2 | Certificates of deposit | Non-US
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	50.2	77.7
Level 2 | Commercial paper
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	7.8	0.0
Level 2 | Variable rate demand note
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	16.9	0.0
Level 2 | Money market funds
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Level 2 | Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	15.0	0.0
Level 2 | U.S. agency securities
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	18.8	0.0
Level 2 | U.S. treasury securities
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Level 2 | Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	105.8	34.6
Level 2 | Commercial paper
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	1.0	0.3
Level 3
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Total short-term investments	0.0	0.0
Common stock of non-U.S. corporations	0.0	0.0
Total assets	0.0	0.0
Level 3 | Municipal bonds
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 3 | Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 3 | U.S. agency securities
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 3 | U.S. treasury securities
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 3 | Certificates of deposit | United States
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 3 | Certificates of deposit | Non-US
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 3 | Commercial paper
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 3 | Variable rate demand note
Assets, Fair Value Disclosure [Abstract]
Total short-term investments	0.0	0.0
Level 3 | Money market funds
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Level 3 | Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Level 3 | U.S. agency securities
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Level 3 | U.S. treasury securities
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Level 3 | Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	0.0	0.0
Level 3 | Commercial paper
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents	$ 0.0	$ 0.0