Stockholders' Equity - Summary of Changes in Accumulated Balance of Other Comprehensive Income (loss) Attributable to MGM Resorts International by Component (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ 10,469,791	$ 11,611,124	$ 9,941,957
Other comprehensive loss	(635)	(9,446)	(35,193)
Other changes in accumulated other comprehensive income (loss):
Accumulated other comprehensive loss	(10,202)	(8,556)
Ending Balance	12,662,919	10,469,791	11,611,124
Empire City Transaction [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	(5,027)
MGM Growth Properties LLC [Member] | Class A Shareholders [Member]
Other changes in accumulated other comprehensive income (loss):
Share issuance	1,201,558		361,622
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(18,872)	(11,450)	12,545
Other comprehensive income (loss) before reclassifications	28,870	(13,022)	(43,188)
Amounts reclassified from accumulated other comprehensive income (loss) to "Interest expense, net"	0	0	0
Amounts reclassified from accumulated other comprehensive loss related to de-designation of interest rate swaps to "Other, net"	0
Other comprehensive loss	28,870	(13,022)	(43,188)
Other changes in accumulated other comprehensive income (loss):
Other	0
Accumulated other comprehensive loss	28,870
Other comprehensive (income) loss attributable to noncontrolling interest	(12,745)	5,600	19,193
Ending Balance	(2,747)	(18,872)	(11,450)
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest | Empire City Transaction [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	0
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest | MGM Growth Properties LLC [Member] | Class A Shareholders [Member]
Other changes in accumulated other comprehensive income (loss):
Share issuance	0
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest | Park MGM Transaction [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	0
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest | Northfield OpCo [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	9,144	6,668	1,434
Other comprehensive income (loss) before reclassifications	(28,783)	4,706	(1,221)
Amounts reclassified from accumulated other comprehensive income (loss) to "Interest expense, net"	(5,599)	(1,130)	9,216
Amounts reclassified from accumulated other comprehensive loss related to de-designation of interest rate swaps to "Other, net"	4,877
Other comprehensive loss	(29,505)	3,576	7,995
Other changes in accumulated other comprehensive income (loss):
Other	0
Accumulated other comprehensive loss	(29,505)
Other comprehensive (income) loss attributable to noncontrolling interest	9,532	(1,100)	(2,761)
Ending Balance	(10,829)	9,144	6,668
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest | Empire City Transaction [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest | MGM Growth Properties LLC [Member] | Class A Shareholders [Member]
Other changes in accumulated other comprehensive income (loss):
Share issuance	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest | Park MGM Transaction [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest | Northfield OpCo [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	0
Accumulated Other Adjustment Including Portion Attributable To Noncontrolling Interest
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	1,172	1,172	1,074
Other comprehensive income (loss) before reclassifications	0	0	98
Amounts reclassified from accumulated other comprehensive income (loss) to "Interest expense, net"	0	0	0
Amounts reclassified from accumulated other comprehensive loss related to de-designation of interest rate swaps to "Other, net"	0
Other comprehensive loss	0	0	98
Other changes in accumulated other comprehensive income (loss):
Other	481
Accumulated other comprehensive loss	2,202
Other comprehensive (income) loss attributable to noncontrolling interest	0	0	0
Ending Balance	3,374	1,172	1,172
Accumulated Other Adjustment Including Portion Attributable To Noncontrolling Interest | Empire City Transaction [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	195
Accumulated Other Adjustment Including Portion Attributable To Noncontrolling Interest | MGM Growth Properties LLC [Member] | Class A Shareholders [Member]
Other changes in accumulated other comprehensive income (loss):
Share issuance	1,512
Accumulated Other Adjustment Including Portion Attributable To Noncontrolling Interest | Park MGM Transaction [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	16
Accumulated Other Adjustment Including Portion Attributable To Noncontrolling Interest | Northfield OpCo [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	(2)
AOCI Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(8,556)	(3,610)	15,053
Other comprehensive income (loss) before reclassifications	87	(8,316)	(44,311)
Amounts reclassified from accumulated other comprehensive income (loss) to "Interest expense, net"	(5,599)	(1,130)	9,216
Amounts reclassified from accumulated other comprehensive loss related to de-designation of interest rate swaps to "Other, net"	4,877
Other comprehensive loss	(635)	(9,446)	(35,095)
Other changes in accumulated other comprehensive income (loss):
Other	481
Accumulated other comprehensive loss	1,567
Other comprehensive (income) loss attributable to noncontrolling interest	(3,213)	4,500	16,432
Ending Balance	(10,202)	$ (8,556)	$ (3,610)
AOCI Including Portion Attributable to Noncontrolling Interest | Empire City Transaction [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	195
AOCI Including Portion Attributable to Noncontrolling Interest | MGM Growth Properties LLC [Member] | Class A Shareholders [Member]
Other changes in accumulated other comprehensive income (loss):
Share issuance	1,512
AOCI Including Portion Attributable to Noncontrolling Interest | Park MGM Transaction [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	16
AOCI Including Portion Attributable to Noncontrolling Interest | Northfield OpCo [Member]
Other changes in accumulated other comprehensive income (loss):
Acquisition transaction	$ (2)