REVENUE RECOGNITION - Casino Revenue (Details)	9 Months Ended
Sep. 30, 2018 item
CONSOLIDATED STATEMENTS OF INCOME
Number of components, progressive jackpot provisions	2

The number of components for progressive jackpot provisions recognized.

No definition available.

Name:	mcri_NumberOfComponentsProgressiveJackpotProvisions
Namespace Prefix:	mcri_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration