Borrowings and Credit Arrangements - Interest Expense under Convertible Notes (Detail) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
---|---|---|---|---|
Jul. 01, 2017 |
Jun. 25, 2016 |
Jul. 01, 2017 |
Jun. 25, 2016 |
|
Debt Conversion [Line Items] | ||||
Non-cash interest expense | $ 38.9 | $ 38.8 | ||
Convertible Notes Payable | ||||
Debt Conversion [Line Items] | ||||
Amortization of debt discount | $ 4.4 | $ 5.2 | 14.5 | 17.3 |
Amortization of deferred financing costs | 0.2 | 0.2 | 0.7 | 0.9 |
Principal accretion | 3.9 | 4.2 | 12.8 | 12.4 |
Non-cash interest expense | 8.5 | 9.6 | 28.0 | 30.6 |
2.00% accrued interest (cash) | 1.6 | 2.1 | 5.4 | 8.0 |
Interest expense, net | $ 10.1 | $ 11.7 | $ 33.4 | $ 38.6 |