Condensed Consolidating Financial Information - Consolidating Statement of Operations and Comprehensive Income Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Revenues	$ 220,390	$ 184,456	$ 436,229	$ 368,355
Expenses
Depreciation	67,474	60,227	136,465	121,911
Property transactions, net	14,426	10,587	18,512	17,442
Reimbursable expenses	32,907	20,642	61,267	41,129
Amortization of above market lease, net	172	172	343	343
Acquisition-related expenses	2,131	0	2,672	0
General and administrative	2,755	2,661	6,663	5,341
Expenses, net	119,865	94,289	225,922	186,166
Operating income	100,525	90,167	210,307	182,189
Equity in earnings of subsidiaries	0	0	0	0
Non-operating income (expense)
Interest income	1,278	881	2,310	1,559
Interest expense	(49,276)	(44,818)	(98,506)	(89,454)
Other non-operating expenses	(3,205)	(1,178)	(5,389)	(1,312)
Non-operating income (expense)	(51,203)	(45,115)	(101,585)	(89,207)
Income before income taxes	49,322	45,052	108,722	92,982
Provision for income taxes	(1,263)	(1,177)	(2,494)	(2,415)
Net income	48,059	43,875	106,228	90,567
Other comprehensive income (loss)
Unrealized gain (loss) on cash flow hedges, net	6,281	(4,112)	22,636	(4,746)
Comprehensive income	54,340	39,763	128,864	85,821
Eliminations
Revenues
Revenues	0	0	0	0
Expenses
Depreciation	0	0	0	0
Property transactions, net	0	0	0	0
Reimbursable expenses	0	0	0	0
Amortization of above market lease, net	0	0	0	0
Acquisition-related expenses	0		0
General and administrative	0	0	0	0
Expenses, net	0	0	0	0
Operating income	0	0	0	0
Equity in earnings of subsidiaries	(104,163)	(91,651)	(217,190)	(185,115)
Non-operating income (expense)
Interest income	0	0	0	0
Interest expense	0	0	0	0
Other non-operating expenses	0	0	0	0
Non-operating income (expense)	0	0	0	0
Income before income taxes	(104,163)	(91,651)	(217,190)	(185,115)
Provision for income taxes	0	0	0	0
Net income	(104,163)	(91,651)	(217,190)	(185,115)
Other comprehensive income (loss)
Unrealized gain (loss) on cash flow hedges, net	0	0	0	0
Comprehensive income	(104,163)	(91,651)	(217,190)	(185,115)
Guarantor Subsidiaries \| Reportable Legal Entities
Revenues
Revenues	220,390	184,456	436,229	368,355
Expenses
Depreciation	67,459	60,227	136,423	121,911
Property transactions, net	14,426	10,587	18,512	17,442
Reimbursable expenses	32,907	20,642	61,267	41,129
Amortization of above market lease, net	172	172	343	343
Acquisition-related expenses	0		0
General and administrative	0	0	0	0
Expenses, net	114,964	91,628	216,545	180,825
Operating income	105,426	92,828	219,684	187,530
Equity in earnings of subsidiaries	0	0	0	0
Non-operating income (expense)
Interest income	0	0	0	0
Interest expense	0	0	0	0
Other non-operating expenses	0	0	0	0
Non-operating income (expense)	0	0	0	0
Income before income taxes	105,426	92,828	219,684	187,530
Provision for income taxes	(1,263)	(1,177)	(2,494)	(2,415)
Net income	104,163	91,651	217,190	185,115
Other comprehensive income (loss)
Unrealized gain (loss) on cash flow hedges, net	0	0	0	0
Comprehensive income	104,163	91,651	217,190	185,115
MGP Operating Partnership
Revenues
Revenues	220,390	184,456	436,229	368,355
Expenses
Depreciation	67,474	60,227	136,465	121,911
Property transactions, net	14,426	10,587	18,512	17,442
Reimbursable expenses	32,907	20,642	61,267	41,129
Amortization of above market lease, net	172	172	343	343
Acquisition-related expenses	2,131	0	2,672	0
General and administrative	2,755	2,661	6,663	5,341
Expenses, net	119,865	94,289	225,922	186,166
Operating income	100,525	90,167	210,307	182,189
Non-operating income (expense)
Interest income	1,278	881	2,310	1,559
Interest expense	(49,276)	(44,818)	(98,506)	(89,454)
Other non-operating expenses	(3,205)	(1,178)	(5,389)	(1,312)
Non-operating income (expense)	(51,203)	(45,115)	(101,585)	(89,207)
Income before income taxes	49,322	45,052	108,722	92,982
Provision for income taxes	(1,263)	(1,177)	(2,494)	(2,415)
Net income	48,059	43,875	106,228	90,567
Other comprehensive income (loss)
Unrealized gain (loss) on cash flow hedges, net	6,281	(4,112)	22,636	(4,746)
Comprehensive income	54,340	39,763	128,864	85,821
MGP Operating Partnership \| Reportable Legal Entities
Revenues
Revenues	0	0	0	0
Expenses
Depreciation	15	0	42	0
Property transactions, net	0	0	0	0
Reimbursable expenses	0	0	0	0
Amortization of above market lease, net	0	0	0	0
Acquisition-related expenses	2,131		2,672
General and administrative	2,755	2,661	6,663	5,341
Expenses, net	4,901	2,661	9,377	5,341
Operating income	(4,901)	(2,661)	(9,377)	(5,341)
Equity in earnings of subsidiaries	104,163	91,651	217,190	185,115
Non-operating income (expense)
Interest income	1,278	881	2,310	1,559
Interest expense	(49,276)	(44,818)	(98,506)	(89,454)
Other non-operating expenses	(3,205)	(1,178)	(5,389)	(1,312)
Non-operating income (expense)	(51,203)	(45,115)	(101,585)	(89,207)
Income before income taxes	48,059	43,875	106,228	90,567
Provision for income taxes	0	0	0	0
Net income	48,059	43,875	106,228	90,567
Other comprehensive income (loss)
Unrealized gain (loss) on cash flow hedges, net	6,281	(4,112)	22,636	(4,746)
Comprehensive income	54,340	39,763	128,864	85,821
Co-Issuer \| Reportable Legal Entities
Revenues
Revenues	0	0	0	0
Expenses
Depreciation	0	0	0	0
Property transactions, net	0	0	0	0
Reimbursable expenses	0	0	0	0
Amortization of above market lease, net	0	0	0	0
Acquisition-related expenses	0		0
General and administrative	0	0	0	0
Expenses, net	0	0	0	0
Operating income	0	0	0	0
Equity in earnings of subsidiaries	0	0	0	0
Non-operating income (expense)
Interest income	0	0	0	0
Interest expense	0	0	0	0
Other non-operating expenses	0	0	0	0
Non-operating income (expense)	0	0	0	0
Income before income taxes	0	0	0	0
Provision for income taxes	0	0	0	0
Net income	0	0	0	0
Other comprehensive income (loss)
Unrealized gain (loss) on cash flow hedges, net	0	0	0	0
Comprehensive income	0	0	0	0
Rental Properties
Revenues
Revenues	186,563	163,177	373,126	326,354
Rental Properties \| Eliminations
Revenues
Revenues	0	0	0	0
Rental Properties \| Guarantor Subsidiaries \| Reportable Legal Entities
Revenues
Revenues	186,563	163,177	373,126	326,354
Rental Properties \| MGP Operating Partnership
Revenues
Revenues	186,563	163,177	373,126	326,354
Rental Properties \| MGP Operating Partnership \| Reportable Legal Entities
Revenues
Revenues	0	0	0	0
Rental Properties \| Co-Issuer \| Reportable Legal Entities
Revenues
Revenues	0	0	0	0
Tenant Reimbursements
Revenues
Revenues	33,827	21,279	63,103	42,001
Tenant Reimbursements \| Eliminations
Revenues
Revenues	0	0	0	0
Tenant Reimbursements \| Guarantor Subsidiaries \| Reportable Legal Entities
Revenues
Revenues	33,827	21,279	63,103	42,001
Tenant Reimbursements \| MGP Operating Partnership
Revenues
Revenues	33,827	21,279	63,103	42,001
Tenant Reimbursements \| MGP Operating Partnership \| Reportable Legal Entities
Revenues
Revenues	0	0	0	0
Tenant Reimbursements \| Co-Issuer \| Reportable Legal Entities
Revenues
Revenues	$ 0	$ 0	$ 0	$ 0

Property transactions such as write-downs and impairments.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Total costs of sales and operating expenses for the period.

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