Fresh Start Accounting - Schedule of Changes in Long-Term Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Apr. 23, 2021
Reorganization Chapter11 [Line Items]
Change in long-term debt	$ 306,145	$ 285,982
Reorganization Adjustments
Reorganization Chapter11 [Line Items]
Record 1% premium associated with Exit Notes		749
Reorganization Adjustments | Reorganization, Chapter 11, Predecessor, before Adjustment
Reorganization Chapter11 [Line Items]
Borrowings drawn under the Exit Facilities		200,000
Record payment-in-kind upfront fee related to the Exit RCF		3,478
Issuance of Exit Notes for cash		75,000
Record 1% premium associated with Exit Notes		749
Record backstop commitment premium to payment-in-kind Exit Notes		10,424
Record debt issuance costs related to Exit Term Loans and Exit Notes		(3,669)
Change in long-term debt		$ 285,982