Net Fair Value of Commodity Price Risk (Detail) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Assets	$ 501	$ 291
Liabilities	(8,935)	(10,886)
Net Fair Value	(8,434)	(10,595)
Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Assets	501	291
Liabilities	(8,935)	(10,886)
Net Fair Value	(8,434)	(10,595)
Other Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Assets	501	259
Other Current Assets | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Assets	501	259
Other LongTerm Assets
Derivative Instruments, Gain (Loss) [Line Items]
Assets		32
Other LongTerm Assets | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Assets		32
Other Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(7,732)	(10,247)
Other Current Liabilities | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(7,732)	(10,247)
Other LongTerm Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(1,203)	(639)
Other LongTerm Liabilities | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	$ (1,203)	$ (639)