Borrowings - Summary of Long-term Debt Outstanding (Detail) - USD ($) $ in Millions	Sep. 29, 2017	Sep. 30, 2016
Debt Instrument [Line Items]
Borrowings under credit facilities	$ 350.0	$ 329.6
Debt issuance costs	0.0	(0.6)
Total short-term debt	350.0	379.0
Debt issuance costs	0.0	(0.6)
Long-term debt	0.0	286.9
2017 Revolving Credit Facility
Debt Instrument [Line Items]
Borrowings under credit facilities	$ 350.0	$ 0.0
Weighted-Average Interest Rate (as a percent)	2.36%	0.00%
2013 Term Loan Facility
Debt Instrument [Line Items]
Current portion of 2013 Term Loan Facility	$ 0.0	$ 50.0
Weighted-Average Interest Rate (as a percent)	0.00%	1.65%
Long-term debt	$ 0.0	$ 287.5
2013 Revolving Credit Facility
Debt Instrument [Line Items]
Borrowings under credit facilities	$ 0.0	$ 300.0
Weighted-Average Interest Rate (as a percent)	0.00%	1.91%
Sumitomo Credit Facility
Debt Instrument [Line Items]
Borrowings under credit facilities	$ 0.0	$ 29.6
Weighted-Average Interest Rate (as a percent)	0.00%	0.53%

Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

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Amount, after accumulated amortization, of debt issuance costs classified as noncurrent. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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-Publisher FASB
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Long-term Debt, Current Maturities, Gross

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