Fresh Start Accounting - Accounts Payable and Accrued Liabilities (Details) $ in Thousands	Sep. 18, 2020 USD ($)
Reorganizations [Abstract]
Accrued of professional service provider fees	$ 2,826
Payment of accrued interest and fees on DIP Facility	(1,464)
Reinstatement of accounts payable and accrued liabilities from liabilities subject to compromise	101,431
Accounts payable and accrued liabilities	$ 102,793

Debtor Reorganization Items, increase (cecrease) to accounts payable and accrued liabilities related to payment of accrued interest and fees on DIP facility

No definition available.

Name:	den_DebtorReorganizationItemsIncreaseDecreasetoAPandAccruedsForAccruedInterestandFeesDIP
Namespace Prefix:	den_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant