Net Fair Value of Commodity Price Risk (Detail) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Assets	$ 291	$ 1,611
Liabilities	(10,886)	(2,435)
Net Fair Value	(10,595)	(824)
Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Assets	291	1,611
Liabilities	(10,886)	(2,435)
Net Fair Value	(10,595)	(824)
Other Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Assets	259	1,576
Other Current Assets | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Assets	259	1,576
Other LongTerm Assets
Derivative Instruments, Gain (Loss) [Line Items]
Assets	32	35
Other LongTerm Assets | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Assets	32	35
Other Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(10,247)	(2,435)
Other Current Liabilities | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(10,247)	$ (2,435)
Other LongTerm Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(639)
Other LongTerm Liabilities | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	$ (639)