Fresh Start Accounting (Schedule on Reorganization Items Incurred) (Detail) - Reorganization Adjustments $ in Thousands	Feb. 08, 2019 USD ($)
Fresh-Start Adjustment [Line Items]
Issuance of the equity to the consenting creditors	$ (1,500)
Issuance of the equity related to the emergence vesting of RSUs	(1,318)
Cancellation of Predecessor equity, including vesting	(314,312)
Net Impact to Accumulated deficit	476,511
Predecessor
Fresh-Start Adjustment [Line Items]
Gain on settlement of liabilities subject to compromise	168,952
Issuance of the equity to the consenting creditors	(1,500)
Issuance of the equity related to the emergence vesting of RSUs	(1,318)
Success fees recognized at emergence	(3,592)
Accelerated vesting of Predecessor stock compensation	(396)
Write-off deferred financing costs	(370)
Net impact to Reorganization items, net	161,776
Cancellation of Predecessor equity, including vesting	314,735
Net Impact to Accumulated deficit	$ 476,511