Financial Instruments and Fair Value Disclosures - Additional Information (Detail)	12 Months Ended
Dec. 31, 2019
Fair Value Disclosures [Abstract]
Measurement period for determining fair value of debt instruments	10 days

Measurement period generally used for determining fair value of debt instruments.

No definition available.

Name:	do_GeneralMeasurementPeriodToDetermineFairValueOfDebt
Namespace Prefix:	do_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration