Fresh Start Accounting - Schedule of Net Cash Payments (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Apr. 23, 2021	Dec. 31, 2020
Reorganization Chapter11 [Line Items]
Change in cash and cash equivalents	$ 27,296	$ 79,982	$ 405,869
Reorganization Adjustments | Reorganization, Chapter 11, Predecessor, before Adjustment
Reorganization Chapter11 [Line Items]
Funding of professional fee escrow account		(35,003)
Payment of non-retained professional fees		(14,087)
Payment of Predecessor revolving credit facility, including accrued interest		(479,627)
Proceeds from Exit Facilities		200,000
Receipt of cash from the issuance of Exit Notes through primary Private Placement and primary Rights Offering		75,000
Change in cash and cash equivalents		$ (253,717)