Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative contracts designated as hedging instruments, Assets	$ 13,932	$ 2,948
Derivative contracts not designated as hedging instruments, Assets	284	143
Embedded derivatives, Assets	746	2,485
Derivative contracts designated as hedging instruments, Liabilities	464	7,828
Derivative contracts not designated as hedging instruments, Liabilities	2,440	6,720
Embedded derivatives, Liabilities	2,239	985
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated value of assets held for sale	19,835	26,850
Estimated value of liabilities held for sale	$ 8,908	$ 11,133