SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Credit losses (Details) $ in Millions	24 Months Ended
Dec. 31, 2023 USD ($)
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Reserve for gaming and non-gaming receivables	$ 0.1

Amount of reserve for gaming and non-gaming receivables.

No definition available.

Name:	mcri_ReserveForGamingAndNonGamingReceivables
Namespace Prefix:	mcri_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration