Net Fair Value of Commodity Price Risk (Detail) - USD ($) $ in Thousands	Oct. 07, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Assets	$ 453	$ 1,611
Liabilities	(9,541)	(2,435)
Net Fair Value	(9,088)	(824)
Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Assets	453	1,611
Liabilities	(9,541)	(2,435)
Net Fair Value	(9,088)	(824)
Other Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Assets	277	1,576
Other Current Assets | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Assets	277	1,576
Other LongTerm Assets
Derivative Instruments, Gain (Loss) [Line Items]
Assets	176	35
Other LongTerm Assets | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Assets	176	35
Other Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(9,533)	(2,435)
Other Current Liabilities | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(9,533)	$ (2,435)
Other LongTerm Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	(8)
Other LongTerm Liabilities | Level 1
Derivative Instruments, Gain (Loss) [Line Items]
Liabilities	$ (8)