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Share-Based Compensation Arrangement By Share-Based Payment Award, Absolute Shareholder Return, Percent

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Share-Based Compensation Arrangement By Share-Based Payment Award, Number Of Shares Authorized, Value

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Share-Based Compensation Arrangement By Share-Based Payment Award, Relative Shareholder Return Excess, Rate

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Share-based Compensation Arrangement By Share-based Payment Award, Period During Which Additional Units May Be Earned

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Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Market Capitalization Maximum

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Share-based Compensation Arrangement by Share-based Payment Award, Percent of Distributions

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

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Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders.

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Amount of cash outflow in the form of ordinary dividends provided by the non-wholly owned subsidiary to noncontrolling interests.

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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Maximum number of shares that may be issued in accordance with the plan as a proportion of outstanding capital stock.

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Number of share instruments newly issued under a share-based compensation plan.

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Price of a single share of a number of saleable stocks of a company.

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Percentage of vesting of share-based compensation awards.

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Amount of capitalized and expensed compensation cost from equity-based compensation arrangements.

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Number of shares issued in lieu of cash for services contributed to the entity. Number of shares includes, but is not limited to, shares issued for services contributed by vendors and founders.

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Share-Based Compensation - Narrative (Details) - USD ($)						3 Months Ended	12 Months Ended
	Jun. 02, 2018	Jun. 01, 2018	Jun. 02, 2017	Jun. 02, 2016	Jun. 02, 2015	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Distributions to non-controlling interest holders							$ 585,000	$ 739,000	$ 2,008,000
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders							$ 585,000	$ 739,000	$ 1,633,000
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued for services during the period (in shares)							0	0	0
LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Distributions to non-controlling interest holders							$ 600,000	$ 600,000
LTIP Units \| Annual Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percent							33.30%
LTIP Units \| Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percent							33.30%
LTIP Units \| Interim Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percent							33.30%
Stock Option Plan \| Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)							500,000.0
Shares issued in the period (in shares)							0	0	0
Incentive Restricted Share Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual retainer payable, cash percentage							50.00%
Annual retainer payable, restricted stock units percentage							50.00%
Incentive Restricted Share Plan \| Independent Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual retainer payable							$ 100,000
Incentive Restricted Share Plan \| Non-Executive Chair
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual retainer payable							105,000
Incentive Restricted Share Plan \| Directors, Serving on Committees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual retainer payable							30,000
Incentive Restricted Share Plan \| Unvested restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity based compensation							$ 500,000	$ 700,000	$ 400,000
Incentive Restricted Share Plan \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period							3 years
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum							10.00%
Restricted Share Plan \| Unvested restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost							$ 700,000
Period for recognition							1 year 9 months
Multi-Year Outperformance Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued in the period (in shares)					3,013,933.0666666667
Award vesting period			2 years
Equity based compensation								$ 4,400,000
Equity based compensation, requisite service period							2 years 9 months 35 days
Cumulative compensation expense							$ 1,100,000
Percent of distributions							10.00%
Percent of market capitalization					5.00%
Lock-out period of transferability or liquidity				1 year	1 year
Period during which additional units may be earned							3 years
Multi-Year Outperformance Plan \| Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period					3 years
Multi-Year Outperformance Plan \| Interim Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period					2 years
2018 Multi Year Outperformance Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity based compensation							$ 3,300,000
Share-Based Compensation Arrangement By Share-Based Payment Award, Number Of Shares Authorized, Value		$ 50,000,000
Share price (in dollars per share)		$ 19.57
2018 Multi Year Outperformance Plan \| Annual Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Absolute TSR	24.00%
Relative TSR Excess	(0.0600)
2018 Multi Year Outperformance Plan \| Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Absolute TSR	30.00%
Relative TSR Excess	0.0000
2018 Multi Year Outperformance Plan \| Interim Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Absolute TSR	24.00%
Relative TSR Excess	(0.0600)
2018 Multi Year Outperformance Plan \| LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued in the period (in shares)							2,554,930
Advisor \| LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders						$ 100,000
Advisor \| 2018 Multi Year Outperformance Plan \| LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued in the period (in shares)	2,554,930
Minimum \| Tier One \| 2018 Multi Year Outperformance Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Absolute TSR	24.00%
Minimum \| Tier Two \| 2018 Multi Year Outperformance Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Absolute TSR	36.00%
Maximum \| Tier One \| 2018 Multi Year Outperformance Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Absolute TSR	30.00%
Maximum \| Tier Two \| 2018 Multi Year Outperformance Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Absolute TSR	30.00%