Fresh Start Accounting - Schedule of Liabilities Subject to Compromise were Settled (Detail) - Reorganization Adjustments $ in Thousands	Apr. 23, 2021 USD ($)
Reorganization, Chapter 11 [Line Items]
Senior Notes Claims	$ 2,044,877
Total settled liabilities subject to compromise	2,044,877
Issuance of New Diamond Common Shares to holders of Senior Notes Claims	(639,965)
Issuance of New Diamond Common Shares to participants of the Rights Offering and Private Placements	(274,271)
Record 1% premium associated with First Lien Notes	(749)
Pre-tax gain on settlement of liabilities subject to compromise	$ 1,129,892