Income Taxes Reconciliation (Detail) - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended
Dec. 31, 2016	Sep. 12, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Computed at federal statutory rate	$ (1,854)	$ 369,111	$ (555,916)	$ (189,445)
State income taxes, net of federal income tax benefit	197	1,989	(4,438)	(3,556)
Change in valuation allowance	1,657	(384,692)	554,879	61,104
Effective Income Tax Rate Reconciliation, Reorganization Adjustments, Amount	0	13,572	0	0
Other, net	0	20	104	219
Income tax benefit	$ 0	$ 0	$ (5,371)	$ (131,678)
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Computed at federal statutory rate	35.00%	35.00%	35.00%	35.00%
State income taxes, net of federal income tax benefit	(3.71%)	0.19%	0.30%	0.60%
Valuation allowance	(31.29%)	(36.48%)	(35.00%)	(11.30%)
Effective Income Tax Rate Reconciliation, Reorganization Adjustments, Percent	0.00%	1.29%	0.00%	0.00%
Other, net	0.00%	0.00%	0.00%	0.00%
Effective Income Tax Rate, Continuing Operations, Total	0.00%	0.00%	0.30%	24.30%

Effective Income Tax Rate Reconciliation, Reorganization Adjustments, Amount

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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