Net Fair Value of Commodity Price Risk (Detail) - USD ($) $ in Thousands	Apr. 23, 2016	Jan. 02, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Assets	$ 323
Liabilities	(8,932)	$ (14,887)
Net Fair Value	(8,609)	(14,887)
Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Assets	323
Liabilities	(6,719)	(11,946)
Net Fair Value	(6,396)	(11,946)
Level 2
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(2,213)	(2,941)
Net Fair Value	(2,213)	(2,941)
Other LongTerm Assets
Derivative Instruments, Gain (Loss) [Line Items]
Assets	323
Other LongTerm Assets | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Assets	323
Other Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(8,932)	(14,867)
Other Current Liabilities | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(6,719)	(11,926)
Other Current Liabilities | Level 2
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	$ (2,213)	(2,941)
Other LongTerm Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities		(20)
Other LongTerm Liabilities | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities		$ (20)