Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Statement of Cash Flows Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities
Net cash provided by (used in) operating activities	$ 1,356,108	$ 1,395,466
Cash flows from investing activities
Capital expenditures, net of construction payable	(482,786)	(1,223,924)
Dispositions of property and equipment	1,936	575
Proceeds from sale of business units and investment in unconsolidated affiliate	0	163,616
Investments in unconsolidated affiliates	(81,271)	(2,503)
Distributions from unconsolidated affiliates	99,661	320,287
Intercompany accounts	0	0
Northfield OpCo transaction	0
Other	(31,112)	(22,209)
Net cash used in investing activities	(1,029,253)	(1,798,692)
Cash flows from financing activities
Net borrowings (repayments) under bank credit facilities – maturities of 90 days or less	(1,711,007)	778,101
Issuance of long-term debt	3,250,000	1,000,000
Retirement of senior notes and senior debentures	(1,759,978)	(2,265)
Debt issuance costs	(63,391)	(64,808)
Issuance of MGM Growth Properties Class A shares, net	699,362
Dividends paid to common shareholders	(205,163)	(197,295)
MGP dividends paid to consolidated subsidiaries	0	0
Distributions to noncontrolling interest owners	(172,239)	(149,526)
Purchases of common stock	(638,815)	(1,133,334)
Intercompany accounts	0	0
Other	(18,655)	(23,476)
Net cash provided by (used in) financing activities	(619,886)	207,397
Effect of exchange rate on cash	(162)	(1,489)
Cash flows from (used in) discontinued operations
Cash flows from operating activities	0	0
Cash flows used in investing activities	0	0
Cash flows used in financing activities	0	0
Net cash flows used in discontinued operations	0	0
Change in cash and cash equivalents classified as assets held for sale	0	0
Cash and cash equivalents
Net decrease for the period	(293,193)	(197,318)
Balance, beginning of period	1,526,762	1,499,995
Balance, end of period	1,233,569	1,302,677
Empire City [Member]
Cash flows from investing activities
Acquisition, net of cash acquired	(535,681)	0
Northfield [Member]
Cash flows from investing activities
Acquisition, net of cash acquired	0	(1,034,534)
Reportable Legal Entities [Member] | Parent [Member]
Cash flows from operating activities
Net cash provided by (used in) operating activities	(344,621)	(338,197)
Cash flows from investing activities
Capital expenditures, net of construction payable	0	0
Dispositions of property and equipment	0	0
Proceeds from sale of business units and investment in unconsolidated affiliate		0
Investments in unconsolidated affiliates	0	0
Distributions from unconsolidated affiliates	0	0
Intercompany accounts	0	0
Northfield OpCo transaction	0
Other	0	0
Net cash used in investing activities	0	0
Cash flows from financing activities
Net borrowings (repayments) under bank credit facilities – maturities of 90 days or less	510,000	(144,375)
Issuance of long-term debt	1,000,000	1,000,000
Retirement of senior notes and senior debentures	(1,721,698)	0
Debt issuance costs	(14,080)	(14,414)
Issuance of MGM Growth Properties Class A shares, net	0
Dividends paid to common shareholders	(205,163)	(197,295)
MGP dividends paid to consolidated subsidiaries	0	0
Distributions to noncontrolling interest owners	0	0
Purchases of common stock	(638,815)	(1,133,334)
Intercompany accounts	1,176,224	859,461
Other	(8,789)	(11,594)
Net cash provided by (used in) financing activities	97,679	358,449
Effect of exchange rate on cash	0	0
Cash flows from (used in) discontinued operations
Cash flows from operating activities	0	0
Cash flows used in investing activities	0	0
Cash flows used in financing activities	0	0
Net cash flows used in discontinued operations	0	0
Change in cash and cash equivalents classified as assets held for sale	0	0
Cash and cash equivalents
Net decrease for the period	(246,942)	20,252
Balance, beginning of period	259,738	26,870
Balance, end of period	12,796	47,122
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Cash flows from operating activities
Net cash provided by (used in) operating activities	1,306,819	961,795
Cash flows from investing activities
Capital expenditures, net of construction payable	(334,870)	(541,497)
Dispositions of property and equipment	1,870	477
Proceeds from sale of business units and investment in unconsolidated affiliate		163,616
Investments in unconsolidated affiliates	(81,271)	(2,503)
Distributions from unconsolidated affiliates	99,661	320,287
Intercompany accounts	(1,134,905)	(992,845)
Northfield OpCo transaction	(3,779)
Other	(4,500)	(13,416)
Net cash used in investing activities	(1,993,475)	(998,275)
Cash flows from financing activities
Net borrowings (repayments) under bank credit facilities – maturities of 90 days or less	245,950	0
Issuance of long-term debt	0	0
Retirement of senior notes and senior debentures	(38,280)	(2,265)
Debt issuance costs	0	0
Issuance of MGM Growth Properties Class A shares, net	0
Dividends paid to common shareholders	0	0
MGP dividends paid to consolidated subsidiaries	0	0
Distributions to noncontrolling interest owners	(3,574)	0
Purchases of common stock	0	0
Intercompany accounts	464,988	124,252
Other	(43,291)	(5,714)
Net cash provided by (used in) financing activities	625,793	116,273
Effect of exchange rate on cash	0	0
Cash flows from (used in) discontinued operations
Cash flows from operating activities	0	0
Cash flows used in investing activities	0	0
Cash flows used in financing activities	0	0
Net cash flows used in discontinued operations	0	0
Change in cash and cash equivalents classified as assets held for sale	0	0
Cash and cash equivalents
Net decrease for the period	(60,863)	79,793
Balance, beginning of period	445,423	311,043
Balance, end of period	384,560	390,836
Reportable Legal Entities [Member] | Non-Guarantor MGP Subsidiaries [Member]
Cash flows from operating activities
Net cash provided by (used in) operating activities	(84,517)	424,837
Cash flows from investing activities
Capital expenditures, net of construction payable	0	(191)
Dispositions of property and equipment	0	0
Proceeds from sale of business units and investment in unconsolidated affiliate		0
Investments in unconsolidated affiliates	0	0
Distributions from unconsolidated affiliates	0	0
Intercompany accounts	0	0
Northfield OpCo transaction	3,779
Other	0	0
Net cash used in investing activities	3,779	(1,068,528)
Cash flows from financing activities
Net borrowings (repayments) under bank credit facilities – maturities of 90 days or less	(812,763)	747,375
Issuance of long-term debt	750,000	0
Retirement of senior notes and senior debentures	0	0
Debt issuance costs	(9,983)	(17,490)
Issuance of MGM Growth Properties Class A shares, net	699,362
Dividends paid to common shareholders	0	0
MGP dividends paid to consolidated subsidiaries	(277,899)	(247,820)
Distributions to noncontrolling interest owners	(117,106)	(90,045)
Purchases of common stock	0	0
Intercompany accounts	0	0
Other	(1,342)	0
Net cash provided by (used in) financing activities	230,269	392,020
Effect of exchange rate on cash	0	0
Cash flows from (used in) discontinued operations
Cash flows from operating activities	15,591	8,250
Cash flows used in investing activities	(12)	33,199
Cash flows used in financing activities	(37,900)	0
Net cash flows used in discontinued operations	(22,321)	41,449
Change in cash and cash equivalents classified as assets held for sale	(22,321)	41,449
Cash and cash equivalents
Net decrease for the period	149,531	(251,671)
Balance, beginning of period	3,995	259,722
Balance, end of period	153,526	8,051
Reportable Legal Entities [Member] | Non-Guarantor Other Subsidiaries [Member]
Cash flows from operating activities
Net cash provided by (used in) operating activities	494,018	355,281
Cash flows from investing activities
Capital expenditures, net of construction payable	(147,928)	(682,840)
Dispositions of property and equipment	66	98
Proceeds from sale of business units and investment in unconsolidated affiliate		0
Investments in unconsolidated affiliates	0	0
Distributions from unconsolidated affiliates	0	0
Intercompany accounts	0	0
Northfield OpCo transaction	0
Other	(26,612)	(8,793)
Net cash used in investing activities	(174,474)	(691,535)
Cash flows from financing activities
Net borrowings (repayments) under bank credit facilities – maturities of 90 days or less	(1,654,194)	175,101
Issuance of long-term debt	1,500,000	0
Retirement of senior notes and senior debentures	0	0
Debt issuance costs	(39,328)	(32,904)
Issuance of MGM Growth Properties Class A shares, net	0
Dividends paid to common shareholders	0	0
MGP dividends paid to consolidated subsidiaries	0	0
Distributions to noncontrolling interest owners	(51,559)	(59,481)
Purchases of common stock	0	0
Intercompany accounts	(228,408)	256,952
Other	(3,133)	(6,168)
Net cash provided by (used in) financing activities	(476,622)	333,500
Effect of exchange rate on cash	(162)	(1,489)
Cash flows from (used in) discontinued operations
Cash flows from operating activities	0	0
Cash flows used in investing activities	0	0
Cash flows used in financing activities	0	0
Net cash flows used in discontinued operations	0	0
Change in cash and cash equivalents classified as assets held for sale	0	0
Cash and cash equivalents
Net decrease for the period	(157,240)	(4,243)
Balance, beginning of period	817,606	902,360
Balance, end of period	660,366	898,117
Reportable Legal Entities [Member] | Empire City [Member] | Parent [Member]
Cash flows from investing activities
Acquisition, net of cash acquired	0
Reportable Legal Entities [Member] | Empire City [Member] | Guarantor Subsidiaries [Member]
Cash flows from investing activities
Acquisition, net of cash acquired	(535,681)
Reportable Legal Entities [Member] | Empire City [Member] | Non-Guarantor MGP Subsidiaries [Member]
Cash flows from investing activities
Acquisition, net of cash acquired	0
Reportable Legal Entities [Member] | Empire City [Member] | Non-Guarantor Other Subsidiaries [Member]
Cash flows from investing activities
Acquisition, net of cash acquired	0
Reportable Legal Entities [Member] | Northfield [Member] | Parent [Member]
Cash flows from investing activities
Acquisition, net of cash acquired		0
Reportable Legal Entities [Member] | Northfield [Member] | Guarantor Subsidiaries [Member]
Cash flows from investing activities
Acquisition, net of cash acquired		67,606
Reportable Legal Entities [Member] | Northfield [Member] | Non-Guarantor MGP Subsidiaries [Member]
Cash flows from investing activities
Acquisition, net of cash acquired		(1,068,337)
Reportable Legal Entities [Member] | Northfield [Member] | Non-Guarantor Other Subsidiaries [Member]
Cash flows from investing activities
Acquisition, net of cash acquired		0
Elimination [Member]
Cash flows from operating activities
Net cash provided by (used in) operating activities	(15,591)	(8,250)
Cash flows from investing activities
Capital expenditures, net of construction payable	12	604
Dispositions of property and equipment	0	0
Proceeds from sale of business units and investment in unconsolidated affiliate		0
Investments in unconsolidated affiliates	0	0
Distributions from unconsolidated affiliates	0	0
Intercompany accounts	1,134,905	992,845
Northfield OpCo transaction	0
Other	0	0
Net cash used in investing activities	1,134,917	959,646
Cash flows from financing activities
Net borrowings (repayments) under bank credit facilities – maturities of 90 days or less	0	0
Issuance of long-term debt	0	0
Retirement of senior notes and senior debentures	0	0
Debt issuance costs	0	0
Issuance of MGM Growth Properties Class A shares, net	0
Dividends paid to common shareholders	0	0
MGP dividends paid to consolidated subsidiaries	277,899	247,820
Distributions to noncontrolling interest owners	0	0
Purchases of common stock	0	0
Intercompany accounts	(1,412,804)	(1,240,665)
Other	37,900	0
Net cash provided by (used in) financing activities	(1,097,005)	(992,845)
Effect of exchange rate on cash	0	0
Cash flows from (used in) discontinued operations
Cash flows from operating activities	(15,591)	(8,250)
Cash flows used in investing activities	12	(33,199)
Cash flows used in financing activities	37,900	0
Net cash flows used in discontinued operations	22,321	(41,449)
Change in cash and cash equivalents classified as assets held for sale	22,321	(41,449)
Cash and cash equivalents
Net decrease for the period	22,321	(41,449)
Balance, beginning of period	0	0
Balance, end of period	22,321	(41,449)
Elimination [Member] | Empire City [Member]
Cash flows from investing activities
Acquisition, net of cash acquired	$ 0
Elimination [Member] | Northfield [Member]
Cash flows from investing activities
Acquisition, net of cash acquired		$ (33,803)