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- Definition

Accrued Amortization Expense Relating To Employee Separation

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- Definition

Aggregate Fair Value Of Restricted Shares Granted To Employees and Trustees On Grant Date

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- Definition

Employee service share-based compensation, nonvested awards, expected to be recognized in year one.

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- Definition

Performance measures of core mall non-anchor occupancy period.

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Performance measure of core mall non-anchor occupancy weighted percentage.

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- Definition

Performance measure fixed charge coverage ratio period.

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Performance measures of fixed charge coverage ratio weighted percentage.

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- Definition

Share Based Compensation Common Stock Shares Authorized For Issuance

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- Definition

Share Based Compensation Restricted Share Unit Award Future Compensation Expense

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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- Definition

Amount of cost capitalized for award under share-based payment arrangement.

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- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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- Definition

Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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- Definition

Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of shares issued under share-based payment arrangement.

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Percentage of vesting of award under share-based payment arrangement.

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Share Based Compensation - Additional Information (Details) - USD ($)		12 Months Ended
	Feb. 24, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
2003 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total remaining number of common shares to be issued			1,145,956
Time Based Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate fair value of shares granted			$ 5,600,000	$ 5,100,000	$ 4,800,000
Unrecognized compensation expense			$ 4,313,000
Weighted average period			9 months 18 days
Compensation expense, 2020			$ 2,811,000
Restricted Share Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate compensation expense		$ 1,800,000		$ 2,100,000	1,300,000
Shares vest over period			3 years
Accelerated amortization expense			$ 800,000		$ 400,000
Future aggregate compensation expense			$ 2,800,000
Shares issued			0	0	0
2020 RSUs \| Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted	709,943
Performance measures of core mall non-anchor occupancy period	3 years
Performance measure fixed charge coverage ratio period	3 years
Performance measure of core mall non-anchor occupancy weighted percentage	50.00%
Performance measures of fixed charge coverage ratio weighted percentage.	50.00%
Non-Employee Trustees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate compensation expense			$ 7,000,000.0	$ 6,900,000	$ 5,700,000
Accrued amortization relating to employee separation			1,100,000	100,000	200,000
Income tax benefit for share based compensation arrangements			0
Compensation costs capitalized			200,000	100,000	100,000
Non-Employee Trustees \| Time Based Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate compensation expense			700,000	500,000	500,000
Aggregate fair value of shares granted			700,000	$ 800,000	$ 700,000
Unrecognized compensation expense			$ 284,000
Shares vest over period			1 year
Number of awards granted			114,800	68,698	64,358
Weighted average grant date fair value			$ 6.35	$ 11.17	$ 11.45
Fair value of shares vested			$ 800,000	$ 600,000	$ 800,000
Compensation expense, 2020			284,000
Employees \| Time Based Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate compensation expense			3,700,000	4,300,000	3,900,000
Accrued amortization relating to employee separation			200,000	100,000	200,000
Aggregate fair value of shares granted			4,900,000	$ 4,300,000	$ 4,000,000.0
Unrecognized compensation expense			$ 4,029,000
Number of awards granted			683,570	392,697	245,950
Weighted average grant date fair value			$ 7.15	$ 10.99	$ 16.43
Fair value of shares vested			$ 3,800,000	$ 2,000,000.0	$ 3,900,000
Compensation expense, 2020			$ 2,527,000
Employees \| Time Based Restricted Stock Awards \| Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted	1,093,292
Employees \| Time Based Restricted Stock Awards \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vest over period			1 year
Employees \| Time Based Restricted Stock Awards \| Minimum \| Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vest over period	2 years
Employees \| Time Based Restricted Stock Awards \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vest over period			3 years
Employees \| Time Based Restricted Stock Awards \| Maximum \| Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vest over period	3 years
Employees \| Outperformance Units (“OPUs”)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate compensation expense			$ 800,000
Accrued amortization relating to employee separation			$ 100,000
Number of awards granted			517,783
Employees \| Outperformance Units (“OPUs”) \| Vest Immediately
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting, percentage			50.00%
Employees \| Outperformance Units (“OPUs”) \| Subject to an Additional One-year Vesting Requirement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vest over period			1 year
Awards vesting, percentage			25.00%
Employees \| Outperformance Units (“OPUs”) \| Subject to an Additional Two-year Vesting Requirement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vest over period			2 years
Awards vesting, percentage			25.00%