Income Taxes (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Income Taxes [Line Items]
United States tax rate	35.00%	35.00%	35.00%
Foreign tax rate difference	$ (179.4)	$ (164.1)	$ (120.9)
Federal research and development tax credit		11.6	$ 11.0
Adjustment to previous tax returns	$ 1.2	2.6
Benefit to tax expense		24.0
Income tax holiday	Sep. 30, 2020
Impact of tax holiday	$ 37.4	$ 30.8
Impact of tax holiday on diluted earnings per share (in dollars per share)	$ 0.20	$ 0.16
Valuation Allowance, Amount	$ 90.9	$ 79.1
Tax benefit to recognize if valuation allowance is reversed	90.9
Future taxable income needed to utilize deferred tax assets	141.6
Federal net operating loss carry forwards	$ 8.8
Operating loss carryforwards, expiration date	Dec. 31, 2035
Undistributed earnings of foreign subsidiaries	$ 2,260.4
Total unrecognized tax benefits that would impact the effective tax rate	72.9
Previously unrecognized tax benefits related to the expiration of the statute of limitations	0.3
Decreases relating to settlements with taxing authorities	2.6
Accrued interest or penalties related to unrecognized tax benefit	2.6
Foreign Tax Authority [Member]
Income Taxes [Line Items]
Valuation Allowance, Amount	19.9
State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Valuation Allowance, Amount	71.0
Tax credit carryforward	$ 71.0
UNITED STATES
Income Taxes [Line Items]
Open tax year	1999
CALIFORNIA
Income Taxes [Line Items]
Open tax year	1999
CANADA
Income Taxes [Line Items]
Open tax year	2012
LUXEMBOURG
Income Taxes [Line Items]
Open tax year	2011
MEXICO
Income Taxes [Line Items]
Open tax year	2009
SINGAPORE
Income Taxes [Line Items]
Open tax year	2011