Investments, Forward Contracts and Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Millions	Jun. 29, 2019	Jun. 30, 2018
Assets:
Total debt available-for-sale securities	$ 0.6	$ 189.6
Liability:
Foreign currency forward contracts	4.0	11.7
Fair value of contingent consideration	38.4
Contingent liability, noncurrent	37.7	0.0
Contingent liability, current	0.7
U.S. treasuries
Assets:
Total debt available-for-sale securities		35.9
U.S. agencies
Assets:
Total debt available-for-sale securities		13.2
Municipal bonds and sovereign debt instruments
Assets:
Total debt available-for-sale securities		2.7
Asset-backed securities
Assets:
Total debt available-for-sale securities	0.6	23.5
Corporate securities
Assets:
Total debt available-for-sale securities		114.3
Recurring basis
Assets:
Total debt available-for-sale securities	0.6	189.6
Marketable equity securities	0.0	0.0
Money market funds	322.9	354.9
Trading securities	1.5	1.6
Foreign currency forward contracts	1.2	2.7
Total assets	326.2	548.8
Liability:
Foreign currency forward contracts	4.0	11.7
Fair value of contingent consideration	38.4	0.0
Total liabilities	42.4	11.7
Recurring basis | Cash and cash equivalents
Assets:
Total assets	315.5	364.8
Recurring basis | Short-term investments
Assets:
Total assets	1.5	169.3
Recurring basis | Restricted cash
Assets:
Total assets	3.5	7.3
Recurring basis | Other current assets
Assets:
Total assets	1.2	2.7
Recurring basis | Other non-current assets
Assets:
Total assets	4.5	4.7
Recurring basis | Other current liabilities
Liability:
Total liabilities	4.0	11.7
Recurring basis | U.S. treasuries
Assets:
Total debt available-for-sale securities	0.0	35.9
Recurring basis | U.S. agencies
Assets:
Total debt available-for-sale securities	0.0	13.2
Recurring basis | Municipal bonds and sovereign debt instruments
Assets:
Total debt available-for-sale securities	0.0	2.7
Recurring basis | Asset-backed securities
Assets:
Total debt available-for-sale securities	0.6	23.5
Recurring basis | Corporate securities
Assets:
Total debt available-for-sale securities	0.0	114.3
Recurring basis | Certificate of deposits
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 1
Assets:
Total debt available-for-sale securities	0.0	35.9
Marketable equity securities	0.0	0.0
Money market funds	322.9	354.9
Trading securities	1.5	1.6
Foreign currency forward contracts	0.0	0.0
Total assets	324.4	392.4
Liability:
Foreign currency forward contracts	0.0	0.0
Fair value of contingent consideration	0.0	0.0
Total liabilities	0.0	0.0
Recurring basis | Level 1 | U.S. treasuries
Assets:
Total debt available-for-sale securities	0.0	35.9
Recurring basis | Level 1 | U.S. agencies
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 1 | Municipal bonds and sovereign debt instruments
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 1 | Asset-backed securities
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 1 | Corporate securities
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 1 | Certificate of deposits
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 2
Assets:
Total debt available-for-sale securities	0.6	153.7
Marketable equity securities	0.0	0.0
Money market funds	0.0	0.0
Trading securities	0.0	0.0
Foreign currency forward contracts	1.2	2.7
Total assets	1.8	156.4
Liability:
Foreign currency forward contracts	4.0	11.7
Fair value of contingent consideration	0.0	0.0
Total liabilities	4.0	11.7
Recurring basis | Level 2 | U.S. treasuries
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 2 | U.S. agencies
Assets:
Total debt available-for-sale securities	0.0	13.2
Recurring basis | Level 2 | Municipal bonds and sovereign debt instruments
Assets:
Total debt available-for-sale securities	0.0	2.7
Recurring basis | Level 2 | Asset-backed securities
Assets:
Total debt available-for-sale securities	0.6	23.5
Recurring basis | Level 2 | Corporate securities
Assets:
Total debt available-for-sale securities	0.0	114.3
Recurring basis | Level 2 | Certificate of deposits
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 3
Assets:
Total debt available-for-sale securities	0.0	0.0
Marketable equity securities	0.0	0.0
Money market funds	0.0	0.0
Trading securities	0.0	0.0
Foreign currency forward contracts	0.0	0.0
Total assets	0.0	0.0
Liability:
Foreign currency forward contracts	0.0	0.0
Fair value of contingent consideration	38.4	0.0
Total liabilities	38.4	0.0
Recurring basis | Level 3 | U.S. treasuries
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 3 | U.S. agencies
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 3 | Municipal bonds and sovereign debt instruments
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 3 | Asset-backed securities
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 3 | Corporate securities
Assets:
Total debt available-for-sale securities	0.0	0.0
Recurring basis | Level 3 | Certificate of deposits
Assets:
Total debt available-for-sale securities	$ 0.0	$ 0.0