COMMITMENTS AND CONTINGENCIES (Details) - USD ($)			3 Months Ended	12 Months Ended
	Feb. 25, 2025	Feb. 14, 2025	Dec. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2024
COMMITMENTS AND CONTINGENCIES
Awarded damages, Value		$ 74,772,551
Negligence and gross negligence counterclaims amount		144,894
Principal judgment amount	$ 74,600,000	74,627,657	$ 27,600,000
Estimated Litigation Liability, Current							$ 47,000,000.0
Litigation expense recognized				$ 800,000	$ 6,900,000	$ 7,300,000
Professional service fees relating to our construction litigation				800,000	6,900,000	7,300,000
Supersedeas Bond		$ 25,000,000
Lawsuit With Pcl Construction Services Inc
COMMITMENTS AND CONTINGENCIES
Litigation expense recognized				800,000	6,900,000	7,300,000
Professional service fees relating to our construction litigation				800,000	$ 6,900,000	$ 7,300,000
Monarch Black Hawk, Inc. (owner of Monarch Casino Black Hawk) | Self-Insurance
COMMITMENTS AND CONTINGENCIES
Individual health care liability retained			250,000	250,000
workers compensation deduction, Per claim			10,000	10,000
Monarch Black Hawk, Inc. (owner of Monarch Casino Black Hawk) | Self-Insurance | Minimum
COMMITMENTS AND CONTINGENCIES
Additional reinsurance			500,000	500,000
Monarch Black Hawk, Inc. (owner of Monarch Casino Black Hawk) | Self-Insurance | Maximum
COMMITMENTS AND CONTINGENCIES
Additional reinsurance			1,000,000	1,000,000
Golden Road Motor Inn, Inc. (owner and operator of Atlantis) | Self-Insurance
COMMITMENTS AND CONTINGENCIES
Individual health care liability retained			250,000	$ 250,000
Liability for claims in excess of stop loss (as a percent)				10.00%
Maximum claim liability for workers' compensation			$ 500,000	$ 500,000