Fresh Start Accounting (Schedule of Liabilities Subject of Compromise) (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Feb. 08, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total liabilities subject to compromise	$ 0
Predecessor Company
Debt Instrument [Line Items]
Total liabilities subject to compromise			$ 323,854
Reorganization Adjustments | Predecessor Company
Debt Instrument [Line Items]
Accrued interest on Senior Secured Notes due 2021 and PIK Notes due 2021		$ 20,624
General Unsecured Claims & Convenience Claims		1,749
Preferred stock accrued dividends		14,649
Total liabilities subject to compromise		321,495
Issuance of the equity to the holders of the Senior Secured Notes due 2021 and PIK Notes due 2021		(71,343)
Issuance of Successor 10% PIK Notes		(80,000)
GUC Administration Funding		(1,200)
Gain on settlement of liabilities subject to compromise		168,952
Reorganization Adjustments | Senior Notes | 10% Senior Secured Notes due 2021 | Predecessor Company
Debt Instrument [Line Items]
10% Senior Notes		9,427
Reorganization Adjustments | Payment in Kind (PIK) Note | 10% Senior Secured PIK Notes due 2021 | Predecessor Company
Debt Instrument [Line Items]
10% Senior Notes		$ 275,046