Consolidated Balance Sheets - USD ($) $ in Millions	3 Months Ended
	Dec. 27, 2019	Sep. 27, 2019
Statement of Financial Position [Abstract]
Document Period End Date	Dec. 27, 2019
Current assets:
Cash and cash equivalents	$ 928.2	$ 851.3
Marketable Securities, Current	262.2	203.3
Receivables, net of allowance of $0.8 and $0.8, respectively	426.8	465.3
Inventory	604.4	609.7
Other current assets	124.9	105.0
Total current assets	2,346.5	2,234.6
Property, plant and equipment, net	1,190.8	1,205.6
Operating Lease, Right-of-Use Asset	159.1	0.0
Goodwill	1,189.8	1,189.8
Intangible assets, net	96.5	107.9
Deferred tax assets, net	39.9	40.8
Marketable Securities, Noncurrent	38.2	27.6
Other long-term assets	31.0	33.3
Total assets	5,091.8	4,839.6
Current liabilities:
Accounts payable	138.5	190.5
Accrued compensation and benefits	79.9	76.0
Other current liabilities	114.8	107.5
Total current liabilities	333.2	374.0
Long-term tax liabilities	309.5	312.4
Operating Lease, Liability, Noncurrent	150.9	0.0
Other long-term liabilities	30.9	30.9
Total liabilities	824.5	717.3
Stockholders’ equity:
Preferred stock, no par value: 25.0 shares authorized, no shares issued	0.0	0.0
Common stock, $0.25 par value: 525.0 shares authorized; 231.5 shares issued and 170.5 shares outstanding at December 27, 2019, and 230.2 shares issued and 170.1 shares outstanding at September 27, 2019	42.6	42.5
Additional paid-in capital	3,251.9	3,188.0
Treasury stock, at cost	(3,513.8)	(3,412.9)
Retained earnings	4,494.6	4,312.6
Accumulated other comprehensive loss	(8.0)	(7.9)
Total stockholders’ equity	4,267.3	4,122.3
Total liabilities and stockholders’ equity	$ 5,091.8	$ 4,839.6