Chapter 11 Proceedings - Schedule of Reorganization Items Incurred (Detail) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended	4 Months Ended	6 Months Ended
	Apr. 23, 2021	Jun. 30, 2021	Jun. 30, 2020	Apr. 23, 2021	Jun. 30, 2020
Reorganizations [Abstract]
Professional fees	$ 25,414	$ 5,538	$ 20,659	$ 51,084	$ 20,659
Fresh start valuation adjustments	2,699,422			2,699,422
Net gain on settlement of liabilities subject to compromise	(1,129,892)			(1,129,892)
Accrued backstop commitment premium				10,424
Write-off of predecessor directors and officers insurance	6,932			6,932
Other	2,636		(714)	1,793	(714)
Write-off of debt issuance costs			27,493		27,493
Adjustments for estimated claims and rejected contracts			6,539		6,539
Total reorganization items, net	$ 1,604,512	$ 5,538	$ 53,977	$ 1,639,763	$ 53,977