Income Taxes Reconciliation (Detail) - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 12, 2016	Dec. 31, 2018	Dec. 31, 2017
Income Tax Rate Reconciliation [Line Items]
Computed at federal statutory rate			$ 9,700
State income taxes, net of federal income tax benefit			(1,400)
Change in valuation allowance			(24,400)
Effective Income Tax Rate Reconciliation, Reorganization Adjustments, Amount			10,800
Other, net			300
Income tax benefit			$ 4,900
Effective Income Tax Rate Reconciliation, Percent			0.20%
Computed at federal statutory rate			3500.00%
Predecessor [Member]
Income Tax Rate Reconciliation [Line Items]
Computed at federal statutory rate		$ 369,111
State income taxes, net of federal income tax benefit		1,989
Change in valuation allowance		(384,692)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		0
Effective Income Tax Rate Reconciliation, Reorganization Adjustments, Amount		13,572
Other, net		20
Income tax benefit		$ 0
Effective Income Tax Rate Reconciliation, Percent		0.00%
Computed at federal statutory rate		35.00%
State income taxes, net of federal income tax benefit		0.20%
Change in valuation allowance		(36.50%)
Effective Income Tax Rate Reconciliation, Effect of rate change on valuation allowance, Amount		$ 0
Effective Income Tax Rate Reconciliation, Effect of rate change on valuation allowance, Percent		0.00%
Effect of rate change		0.00%
Reorganization adjustments		1.30%
Other, net		0.00%
Successor [Member]
Income Tax Rate Reconciliation [Line Items]
Computed at federal statutory rate	$ (1,854)		$ 47,315	$ 9,701
State income taxes, net of federal income tax benefit	197		1,743	(1,383)
Change in valuation allowance	1,657		(48,820)	(24,353)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	0		0	86,612
Effective Income Tax Rate Reconciliation, Reorganization Adjustments, Amount	0		0	10,760
Other, net	0		285	332
Income tax benefit	$ 0		$ 523	$ (4,943)
Effective Income Tax Rate Reconciliation, Percent	0.00%		0.20%	(17.80%)
Computed at federal statutory rate	35.00%		21.00%	35.00%
State income taxes, net of federal income tax benefit	(3.70%)		0.00%	(5.00%)
Change in valuation allowance	(31.30%)		(21.70%)	(87.80%)
Effective Income Tax Rate Reconciliation, Effect of rate change on valuation allowance, Amount	$ 0		$ 0	$ (86,612)
Effective Income Tax Rate Reconciliation, Effect of rate change on valuation allowance, Percent	0.00%		0.00%	(312.50%)
Effect of rate change	0.00%		0.00%	0.00%
Reorganization adjustments	0.00%		0.00%	38.80%
Other, net	0.00%		0.00%	1.20%