Summary of Significant Accounting Policies (Details) $ in Thousands		3 Months Ended			9 Months Ended
	Jan. 01, 2020 USD ($)	Sep. 30, 2020 USD ($)		Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segment shares		Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Operating Segments
Number of Reportable Operating Segments | segment					2
Revenue Recognition [Abstract]
Straight Line Rent							$ 1,400
Straight line rent write off					$ 36,900		10,000
Percentage rents					5,500		8,500
Concentrations of Risk [Abstract]
Rental revenue		$ 55,591		$ 150,962	288,165		438,257
Share-based Payment Arrangement, Noncash Expense [Abstract]
Share-based payment arrangement, noncash expense included in severance							500
Financing Receivable, Allowance for Credit Loss	$ 2,163	12,546		0	12,546		0
Provision for Loan, Lease, and Other Losses					10,383
Financing Receivable, Credit Loss, Expense (Reversal)		5,707		0	10,383		0
Deferred Costs		35,100			35,100			$ 37,200
Prepaymentfee					0		2,700
Recovery of Direct Costs					8,900		11,300
Rent Abatements					6,800
Deferred Rent Receivables, Net		75,400			75,400
Loans and Leases Receivable, Deferred Income		3,600			3,600
Asset Impairment Charges		11,561		0	62,825		0
Impairment charges on joint ventures		0		0	3,247		0
Line of Credit, Current		750,000			$ 750,000
Number of common shares repurchased | shares					4,066,716
Treasury Stock, Value, Acquired, Cost Method					$ 106,000
number of theatres in entertainment districts | segment					7
Mortgage and other participating interest income							600
Deferred Tax Assets, Valuation Allowance		18,000			$ 18,000
Allowance for Loan and Lease Losses, Write-offs					62,600
Operating Lease, Lease Income		$ 54,785	[1]	145,031	$ 283,891	[1]	420,768
American Multi-Cinema, Inc. [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Triple net lease term		14			14
Number of Properties Allowed to Remove		3			3
Number of Properties with Transitional Leases		7			7
Number of Properties in Master Lease		46			46
Percentage Rent, Percentage		15.00%			15.00%
Number of Years in Lease Extension		5			5
Number of Properties Subject to Lease		53			53
Rent Escalation Term		5			5
Fixed Rent Escalator		7.50%			7.50%
Lessor, Operating Lease, Option to Extend		3			3
American Multi-Cinema, Inc. [Member] | Master Lease [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Annual Rent Reduction, Amount					$ 19,400
Operating Lease, Lease Income					87,800
Other Commitment		$ 35,000			35,000
American Multi-Cinema, Inc. [Member] | Transitional [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Annual Rent Reduction, Amount					6,200
Operating Lease, Lease Income					8,100
TopGolf [Member]
Concentrations of Risk [Abstract]
Rental revenue					$ 60,330		$ 57,592
Percentage of lease revenue in total revenue					18.80%		11.00%
American Multi-Cinema, Inc. [Member]
Concentrations of Risk [Abstract]
Rental revenue					$ 26,226		$ 92,409
Percentage of lease revenue in total revenue					8.20%		17.60%
Regal [Member]
Concentrations of Risk [Abstract]
Rental revenue					$ 12,259		$ 53,807
Percentage of lease revenue in total revenue					3.80%		10.20%
Minimum [Member] | American Multi-Cinema, Inc. [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Number of Properties Allowed to Remove		2			2
Maximum [Member] | American Multi-Cinema, Inc. [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Number of Properties Allowed to Remove		10			10
Restricted Share Units [Member] | Non-Employee Trustees [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Share based compensation expense related to employees and trustees					$ 1,600		$ 1,400
Performance Shares [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Share based compensation, future vesting period minimum (in years)					3 years
Share based compensation expense related to employees and trustees					$ 700
Restricted Stock [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Share based compensation expense related to employees and trustees					$ 8,000		8,500
Restricted Stock [Member] | Minimum [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Share based compensation, future vesting period minimum (in years)					3 years
Restricted Stock [Member] | Maximum [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Share based compensation, future vesting period minimum (in years)					4 years
Share Options [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Share based compensation, future vesting period minimum (in years)					4 years
Stock-option expense					$ 9		7
Revolving Credit Facility [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Deferred Costs		$ 3,700			3,700			$ 3,500
triple-net lessor costs [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Recovery of Direct Costs					1,400		5,800
Ground Lease Arrangement [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Operating Lease, Lease Income		806	[2]	5,931	4,274	[2]	17,489
Ground Lease Arrangement [Member] | American Multi-Cinema, Inc. [Member] | Master Lease [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Operating Lease, Lease Income					6,800
Ground Lease Arrangement [Member] | American Multi-Cinema, Inc. [Member] | Transitional [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Operating Lease, Lease Income					1,200
Discontinued Operations, Disposed of by Sale [Member]
Revenue Recognition [Abstract]
Straight Line Rent							1,200
Straight line rent write off							2,400
Discontinued Operations [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Prepaymentfee							1,800
Mortgage Receivable [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Financing Receivable, Allowance for Credit Loss	2,000	5,684			5,684
Provision for Loan, Lease, and Other Losses					3,684
Notes Receivable [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Financing Receivable, Allowance for Credit Loss	49	6,718			6,718
Provision for Loan, Lease, and Other Losses					6,669
Notes Receivable [Member] | Note, 8.0%, due May 2, 2024 [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Provision for Loan, Lease, and Other Losses					6,500
Financing Receivable, Accrued Interest, Writeoff					300
straight-line receivable [Member]
Revenue Recognition [Abstract]
Straight line rent write off		20,400			25,400
Ground Lease Straight Line Receivable [Member]
Revenue Recognition [Abstract]
Straight line rent write off		3,500			$ 11,500
Building [Member] | Minimum [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Property, Plant and Equipment, Useful Life					30 years
Building [Member] | Maximum [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Property, Plant and Equipment, Useful Life					40 years
Furniture, fixtures & equipment [Member] | Minimum [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Property, Plant and Equipment, Useful Life					3 years
Furniture, fixtures & equipment [Member] | Maximum [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Property, Plant and Equipment, Useful Life					25 years
Building Improvements [Member] | Minimum [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Property, Plant and Equipment, Useful Life					10 years
Building Improvements [Member] | Maximum [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Property, Plant and Equipment, Useful Life					20 years
Experiential Reportable Operating Segment [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Other Commitment		125,900			$ 125,900
Retained Earnings [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Financing Receivable, Credit Loss, Expense (Reversal)	2,200
Retained Earnings [Member] | Mortgage Receivable [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Financing Receivable, Credit Loss, Expense (Reversal)	2,100
Retained Earnings [Member] | Notes Receivable [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Financing Receivable, Credit Loss, Expense (Reversal)	$ 100
Experiential Reportable Operating Segment [Member]
Concentrations of Risk [Abstract]
Rental revenue		40,270		133,620	243,134		386,907
Experiential Reportable Operating Segment [Member] | Real Estate Investment [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Asset Impairment Charges					47,800
Experiential Reportable Operating Segment [Member] | Right-of-Use Assets, Operating Lease [Member]
Share-based Payment Arrangement, Noncash Expense [Abstract]
Asset Impairment Charges		$ 0	[3]	$ 0	$ 15,009	[3]	$ 0
Theatre Project China Member
Share-based Payment Arrangement, Noncash Expense [Abstract]
Number of unconsolidated real estate joint ventures		3			3

[1] (1) During the three and nine months ended September 30, 2020, the Company wrote-off straight-line rent receivables totaling $20.4 million and $25.4 million, respectively, to straight-line rental revenue classified in rental revenue in the accompanying consolidated statements of (loss) income and comprehensive (loss) income. Additionally, during the three and nine months ended September 30, 2020, the Company wrote-off lease receivables from tenants totaling $22.8 million and $23.0 million, respectively, to minimum rent and percentage rent classified in rental revenue in the accompanying consolidated statements of (loss) income and comprehensive (loss) income related to tenants being recognized on a cash basis.

[2] (2) During the three and nine months ended September 30, 2020, the Company wrote-off sub-lessor ground lease straight-line rent receivables totaling $3.5 million and $11.5 million, respectively, to straight-line rental revenue classified in rental revenue in the accompanying consolidated statements of (loss) income and comprehensive (loss) income. Additionally, during both the three and nine months ended September 30, 2020, the Company wrote-off sub-lessor ground lease receivables from tenants totaling $1.4 million to minimum rent classified in rental revenue in the accompanying consolidated statements of (loss) income and comprehensive (loss) income related to tenants being recognized on a cash basis.

[3] (3) During the nine months ended September 30, 2020, the Company recognized impairment charges of $15.0 million related to the operating lease right-of-use assets at two of its properties. See Note 4 for the details on these impairments.