Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Balance Sheet Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Condensed Balance Sheet Statements Captions [Line Items]
Current assets	$ 2,208,024			$ 2,376,355
Property and equipment, net	20,733,381			19,635,459
Investments in subsidiaries	0			0
Investments in the MGP Operating Partnership	0			0
Investments in and advances to unconsolidated affiliates	666,210			1,033,297
Intercompany accounts	0			0
Other non-current assets	6,365,900			6,114,931
Total assets	29,973,515			29,160,042
Current liabilities	2,977,590			3,138,297
Intercompany accounts	0			0
Deferred income taxes, net	1,241,036			1,295,375
Long-term debt, net	14,663,972			12,751,052
Other long-term obligations	251,399			284,416
Total liabilities	19,133,997			17,469,140
Redeemable noncontrolling interests	93,339			79,778
MGM Resorts International stockholders' equity	6,773,358			7,577,061
Noncontrolling interests	3,972,821			4,034,063
Total stockholders' equity	10,746,179	$ 10,839,941	$ 11,400,371	11,611,124	$ 10,295,451	$ 10,202,460	$ 10,112,927	$ 9,941,957
Total liabilities and stockholders' equity	29,973,515			29,160,042
Reportable Legal Entities [Member] | Parent [Member]
Condensed Balance Sheet Statements Captions [Line Items]
Current assets	70,531			78,909
Property and equipment, net	0			0
Investments in subsidiaries	22,171,696			21,040,147
Investments in the MGP Operating Partnership	0			0
Investments in and advances to unconsolidated affiliates	0			0
Intercompany accounts	0			0
Other non-current assets	58,703			49,142
Total assets	22,300,930			21,168,198
Current liabilities	139,794			153,159
Intercompany accounts	6,833,245			5,783,578
Deferred income taxes, net	981,445			934,966
Long-term debt, net	7,532,769			6,682,574
Other long-term obligations	40,319			36,860
Total liabilities	15,527,572			13,591,137
Redeemable noncontrolling interests	0			0
MGM Resorts International stockholders' equity	6,773,358			7,577,061
Noncontrolling interests	0			0
Total stockholders' equity	6,773,358			7,577,061
Total liabilities and stockholders' equity	22,300,930			21,168,198
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements Captions [Line Items]
Current assets	1,012,704			1,015,802
Property and equipment, net	13,518,819			13,521,221
Investments in subsidiaries	3,408,952			3,304,768
Investments in the MGP Operating Partnership	3,486,529			3,549,063
Investments in and advances to unconsolidated affiliates	636,544			1,002,903
Intercompany accounts	6,991,345			5,998,499
Other non-current assets	972,334			913,602
Total assets	30,027,227			29,305,858
Current liabilities	1,480,122			1,445,031
Intercompany accounts	0			0
Deferred income taxes, net	0			0
Long-term debt, net	570			2,835
Other long-term obligations	7,225,214			7,268,664
Total liabilities	8,705,906			8,716,530
Redeemable noncontrolling interests	0			0
MGM Resorts International stockholders' equity	21,321,321			20,589,328
Noncontrolling interests	0			0
Total stockholders' equity	21,321,321			20,589,328
Total liabilities and stockholders' equity	30,027,227			29,305,858
Reportable Legal Entities [Member] | Non-Guarantor MGP Subsidiaries [Member]
Condensed Balance Sheet Statements Captions [Line Items]
Current assets	65,249			266,627
Property and equipment, net	10,592,450			10,021,938
Investments in subsidiaries	0			0
Investments in the MGP Operating Partnership	0			0
Investments in and advances to unconsolidated affiliates	0			0
Intercompany accounts	0			0
Other non-current assets	366,521			62,555
Total assets	11,024,220			10,351,120
Current liabilities	188,396			144,537
Intercompany accounts	402			962
Deferred income taxes, net	31,392			28,544
Long-term debt, net	4,684,717			3,934,628
Other long-term obligations	204,110			174,710
Total liabilities	5,109,017			4,283,381
Redeemable noncontrolling interests	0			0
MGM Resorts International stockholders' equity	4,330,767			4,443,089
Noncontrolling interests	1,584,436			1,624,650
Total stockholders' equity	5,915,203			6,067,739
Total liabilities and stockholders' equity	11,024,220			10,351,120
Reportable Legal Entities [Member] | Non-Guarantor Other Subsidiaries [Member]
Condensed Balance Sheet Statements Captions [Line Items]
Current assets	1,065,314			1,022,340
Property and equipment, net	6,436,901			6,125,722
Investments in subsidiaries	0			0
Investments in the MGP Operating Partnership	843,219			862,037
Investments in and advances to unconsolidated affiliates	4,666			5,394
Intercompany accounts	0			0
Other non-current assets	5,011,749			5,134,220
Total assets	13,361,849			13,149,713
Current liabilities	1,398,040			1,609,110
Intercompany accounts	157,698			213,959
Deferred income taxes, net	259,591			360,409
Long-term debt, net	2,445,916			2,131,015
Other long-term obligations	2,251,797			2,305,353
Total liabilities	6,513,042			6,619,846
Redeemable noncontrolling interests	93,339			79,778
MGM Resorts International stockholders' equity	4,367,083			4,040,676
Noncontrolling interests	2,388,385			2,409,413
Total stockholders' equity	6,755,468			6,450,089
Total liabilities and stockholders' equity	13,361,849			13,149,713
Elimination [Member]
Condensed Balance Sheet Statements Captions [Line Items]
Current assets	(5,774)			(7,323)
Property and equipment, net	(9,814,789)			(10,033,422)
Investments in subsidiaries	(25,580,648)			(24,344,915)
Investments in the MGP Operating Partnership	(4,329,748)			(4,411,100)
Investments in and advances to unconsolidated affiliates	25,000			25,000
Intercompany accounts	(6,991,345)			(5,998,499)
Other non-current assets	(43,407)			(44,588)
Total assets	(46,740,711)			(44,814,847)
Current liabilities	(228,762)			(213,540)
Intercompany accounts	(6,991,345)			(5,998,499)
Deferred income taxes, net	(31,392)			(28,544)
Long-term debt, net	0			0
Other long-term obligations	(9,470,041)			(9,501,171)
Total liabilities	(16,721,540)			(15,741,754)
Redeemable noncontrolling interests	0			0
MGM Resorts International stockholders' equity	(30,019,171)			(29,073,093)
Noncontrolling interests	0			0
Total stockholders' equity	(30,019,171)			(29,073,093)
Total liabilities and stockholders' equity	$ (46,740,711)			$ (44,814,847)