The amount of cash retainer fees paid to board directors of the entity.

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The grant date value of the annual restricted stock awards to each independent director.

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The percentage of distributions paid on a unit of the Operating Partnership that participants of the stock-based compensation plan are entitled to receive during the performance period.

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The percentage of retainer fee paid in cash to the eligible directors of the entity.

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The percentage of retainer fee paid in shares to the directors of the company.

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The aggregate grant date fair value of the awards made under the stock-based compensation plan.

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The aggregate grant date target value of the awards made under the stock-based compensation plan.

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Reflects the period as to when the equity-based award expires as specified in the award agreement.

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The number of grants, net of forfeitures of equity instruments that are not stock option plans awarded since inception of the plan.

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The number of shares (or other type of equity) issuable under an equity-based award plan pertaining to grants made during the period, net of forfeitures 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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The number of years in the performance period for the purpose of setting performance goals for a share-based compensation plan.

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

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Aggregate number of common shares reserved for future issuance.

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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 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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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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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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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 authorized for issuance under share-based payment arrangement.

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

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Equity - Stock Based Compensation (Details)		12 Months Ended
Equity - Stock Based Compensation (Details)	Jul. 06, 2011 USD ($) shares	Dec. 31, 2019 USD ($) item $ / shares shares	Dec. 31, 2018 USD ($) item $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 shares	Dec. 31, 2015 shares
Exchange Rights
Limited partners units, exchange ratio \| item		1
Common stock reserved for possible conversion (in shares) \| shares		54,528,976
Restricted stock
Stock-based incentive plan awards
Shares of restricted stock awarded during the year, net of forfeitures \| shares		90,902	51,756	76,660
Weighted average fair value of shares granted during the period (in dollars per share) \| $ / shares		$ 181.94	$ 153.24	$ 170.81
Annual amortization		$ 12,604,000	$ 12,029,000	$ 13,911,000
Compensation expense, net of capitalization		$ 11,000,000.0	$ 7,800,000	$ 9,000,000.0
Restricted stock \| Minimum
Stock-based incentive plan awards
Vesting service period		3 years
Restricted stock \| Maximum
Stock-based incentive plan awards
Vesting service period		4 years
LTIP Retention Award to Chairman and CEO
Stock-based incentive plan awards
Awards earned (in units) \| shares	1,000,000
Grant Date Fair Value	$ 120,300,000
Service period	8 years
LTIP Retention Award to Chairman and CEO \| A Units
Stock-based incentive plan awards
Awards earned (in units) \| shares						360,000
LTIP Retention Award to Chairman and CEO \| B Units
Stock-based incentive plan awards
Awards earned (in units) \| shares					360,000
LTIP Retention Award to Chairman and CEO \| C Units
Stock-based incentive plan awards
Awards earned (in units) \| shares				280,000
1998 Stock Incentive Plan
Stock-based incentive plan awards
Shares reserved for issuance (in shares) \| shares			16,300,000
1998 Stock Incentive Plan \| Audit Committee Chairman
Stock-based incentive plan awards
Retainer			$ 35,000
1998 Stock Incentive Plan \| Compensation Committee Chairman
Stock-based incentive plan awards
Retainer			35,000
1998 Stock Incentive Plan \| Nominating And Governance Committee Chairman
Stock-based incentive plan awards
Retainer			25,000
1998 Stock Incentive Plan \| Audit Committee Member
Stock-based incentive plan awards
Retainer			15,000
1998 Stock Incentive Plan \| Compensation Committee Member
Stock-based incentive plan awards
Retainer			15,000
1998 Stock Incentive Plan \| Nominating And Governance Committee Member
Stock-based incentive plan awards
Retainer			$ 10,000
1998 Stock Incentive Plan \| Automatic Awards for Eligible Directors
Stock-based incentive plan awards
Retainer fee paid cash (as a percent)			50.00%
1998 Stock Incentive Plan \| Independent Director
Stock-based incentive plan awards
Cash retainer			$ 110,000
1998 Stock Incentive Plan \| Lead Director
Stock-based incentive plan awards
Retainer			$ 50,000
1998 Stock Incentive Plan \| Restricted stock
Stock-based incentive plan awards
Total number of shares awarded, net of forfeiture \| shares		5,865,147
1998 Stock Incentive Plan \| Restricted stock \| Automatic Awards for Eligible Directors
Stock-based incentive plan awards
Vesting service period			1 year
Retainer fee paid in restricted shares (as a percent)			50.00%
1998 Stock Incentive Plan \| Restricted stock \| Independent Director
Stock-based incentive plan awards
Grant date value of restricted stock			$ 175,000
1998 Stock Incentive Plan \| Employee Options
Stock-based incentive plan awards
Vesting service period			3 years
Expiration period			10 years
2019 Stock Incentive Plan
Stock-based incentive plan awards
Shares reserved for issuance (in shares) \| shares		8,000,000
2019 Stock Incentive Plan \| Audit Committee Chairman
Stock-based incentive plan awards
Retainer		$ 35,000
2019 Stock Incentive Plan \| Compensation Committee Chairman
Stock-based incentive plan awards
Retainer		35,000
2019 Stock Incentive Plan \| Nominating And Governance Committee Chairman
Stock-based incentive plan awards
Retainer		25,000
2019 Stock Incentive Plan \| Audit Committee Member
Stock-based incentive plan awards
Retainer		15,000
2019 Stock Incentive Plan \| Compensation Committee Member
Stock-based incentive plan awards
Retainer		15,000
2019 Stock Incentive Plan \| Nominating And Governance Committee Member
Stock-based incentive plan awards
Retainer		$ 10,000
2019 Stock Incentive Plan \| Automatic Awards for Eligible Directors
Stock-based incentive plan awards
Retainer fee paid cash (as a percent)		50.00%
2019 Stock Incentive Plan \| Independent Director
Stock-based incentive plan awards
Cash retainer		$ 110,000
2019 Stock Incentive Plan \| Lead Director
Stock-based incentive plan awards
Retainer		$ 50,000
2019 Stock Incentive Plan \| Restricted stock
Stock-based incentive plan awards
Total number of shares awarded, net of forfeiture \| shares		12,178
2019 Stock Incentive Plan \| Restricted stock \| Automatic Awards for Eligible Directors
Stock-based incentive plan awards
Vesting service period		1 year
Retainer fee paid in restricted shares (as a percent)		50.00%
2019 Stock Incentive Plan \| Restricted stock \| Independent Director
Stock-based incentive plan awards
Grant date value of restricted stock		$ 175,000
2019 Stock Incentive Plan \| Employee Options
Stock-based incentive plan awards
Vesting service period		3 years
Expiration period		10 years
LTIP programs
Stock-based incentive plan awards
Percent of distributions of Operating Partnership that participants are entitled to receive during performance period		10.00%
Compensation expense, net of capitalization		$ 15,800,000	$ 12,000,000.0	$ 14,000,000.0
2018 LTIP program \| LTIP Units
Stock-based incentive plan awards
Number of tranches \| item			2
Grant Date Fair Value			$ 12,100,000
2018 LTIP program \| LTIP Units \| Maximum
Stock-based incentive plan awards
Grant Date Fair Value			$ 18,200,000
2018 LTIP program \| LTIP Units \| Tranche A
Stock-based incentive plan awards
Performance period			2 years
Grant Date Fair Value			$ 6,100,000
Grant Date Target Value			$ 6,100,000
2018 LTIP program \| LTIP Units \| Tranche B
Stock-based incentive plan awards
Performance period			3 years
Grant Date Fair Value			$ 6,100,000
Grant Date Target Value			$ 6,100,000
2019 LTIP program \| LTIP Units
Stock-based incentive plan awards
Performance period		3 years
Grant Date Fair Value		$ 9,500,000
Grant Date Target Value		14,700,000
2019 LTIP program \| LTIP Units \| Maximum
Stock-based incentive plan awards
Grant Date Target Value		$ 22,100,000