COMMITMENTS AND CONTINGENCIES (Details) - Self-Insurance	12 Months Ended
	Dec. 31, 2019 USD ($)
Monarch Black Hawk, Inc. (owner of Monarch Casino Black Hawk)
COMMITMENTS AND CONTINGENCIES
Individual health care liability retained	$ 250,000
Golden Road Motor Inn, Inc. (owner and operator of Atlantis)
COMMITMENTS AND CONTINGENCIES
Individual health care liability retained	$ 250,000
Liability for claims in excess of stop loss (as a percent)	10.00%
Maximum claim liability for workers' compensation	$ 500,000