Statutory Reserves - Additional Information (Detail)	12 Months Ended
Dec. 31, 2022
Statutory Reserves [Abstract]
Statutory accounting practices, statutory capital and surplus rate on after tax profits	10.00%
Statutory accounting practices, statutory capital and surplus rate on registered capital	50.00%

Statutory accounting practices, statutory capital and surplus rate on registered capital.

No definition available.

Name:	ddl_StatutoryAccountingPracticesStatutoryCapitalAndSurplusRateOnRegisteredCapital
Namespace Prefix:	ddl_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration