Organization and Summary of Significant Accounting Policies, Pre-Opening Expenses (Details)	12 Months Ended
Jan. 30, 2021
Minimum [Member]
Pre-Opening Expenses [Abstract]
Period to incur pre-opening expenses	30 days
Maximum [Member]
Pre-Opening Expenses [Abstract]
Period to incur pre-opening expenses	45 days

Period of time before a new store is opened when pre-opening expenses are typically incurred, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	olli_StartUpActivitiesPeriodToIncurPreOpeningExpenses
Namespace Prefix:	olli_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration