Income Per Share of Common Stock - Schedule of Diluted Weighted-Average Number of Common and Common Equivalent Shares Adjustments for Potential Dilution of Share-Based Awards Outstanding (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net income (loss) attributable to MGM Resorts International	$ (331,829)	$ 806,869
Adjustment related to redeemable noncontrolling interests	(9,428)	8,070
Net income (loss) available to common stockholders – basic and diluted	$ (341,257)	$ 814,939
Denominator:
Weighted-average common shares outstanding – basic	494,864	495,415
Potential dilution from share-based awards	0	1,569
Weighted-average common and common equivalent shares – diluted	494,864	496,984
Antidilutive share-based awards excluded from the calculation of diluted earnings per share	8,484	3,876