Income Tax - Additional Information (Detail) $ in Millions	Mar. 27, 2020 USD ($)
Income Tax Disclosure [Abstract]
Income tax benefit from carryback of net operating losses	$ (9.7)

Income tax expense benefit from carryback of net operating losses.

No definition available.

Name:	do_IncomeTaxExpenseBenefitFromCarrybackOfNetOperatingLosses
Namespace Prefix:	do_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration