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Derivative and Other Fair Value Instruments - Summary of Fair Value Measurements for Each Major Category of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
--- | --- | --- | --- | ---
Derivatives, Fair Value [Line Items] |  |  |  |
Fair Value Of SERP Investments | $ 134,088 | $ 140,159 |  |
Assets, Fair Value Disclosure | 136,088 | 145,302 |  |
Other Liabilities, Fair Value Disclosure | 134,088 | 140,159 |  |
Liabilities, Fair Value Disclosure | 146,216 | 141,756 |  |
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners | 379,106 | 366,955 | $ 442,092 | $ 566,783
Fair Value Hedges [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivative liability, fair value | 2,277 | 1,597 |  |
Forward Starting Swaps [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivative Asset | 2,000 | 5,143 |  |
Other Liabilities, Forward Starting Swaps | 9,851 |  |  |
Fair Value, Inputs, Level 1 [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Fair Value Of SERP Investments | 134,088 | 140,159 |  |
Assets, Fair Value Disclosure | 134,088 | 140,159 |  |
Other Liabilities, Fair Value Disclosure | 134,088 | 140,159 |  |
Liabilities, Fair Value Disclosure | 134,088 | 140,159 |  |
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners | 0 | 0 |  |
Fair Value, Inputs, Level 1 [Member] | Fair Value Hedges [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivative liability, fair value | 0 | 0 |  |
Fair Value, Inputs, Level 1 [Member] | Forward Starting Swaps [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivative Asset | 0 | 0 |  |
Other Liabilities, Forward Starting Swaps | 0 |  |  |
Fair Value, Inputs, Level 2 [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Fair Value Of SERP Investments | 0 | 0 |  |
Assets, Fair Value Disclosure | 2,000 | 5,143 |  |
Other Liabilities, Fair Value Disclosure | 0 | 0 |  |
Liabilities, Fair Value Disclosure | 12,128 | 1,597 |  |
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners | 379,106 | 366,955 |  |
Fair Value, Inputs, Level 2 [Member] | Fair Value Hedges [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivative liability, fair value | 2,277 | 1,597 |  |
Fair Value, Inputs, Level 2 [Member] | Forward Starting Swaps [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivative Asset | 2,000 | 5,143 |  |
Other Liabilities, Forward Starting Swaps | 9,851 |  |  |
Fair Value, Inputs, Level 3 [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Fair Value Of SERP Investments | 0 | 0 |  |
Assets, Fair Value Disclosure | 0 | 0 |  |
Other Liabilities, Fair Value Disclosure | 0 | 0 |  |
Liabilities, Fair Value Disclosure | 0 | 0 |  |
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners | 0 | 0 |  |
Fair Value, Inputs, Level 3 [Member] | Fair Value Hedges [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivative liability, fair value | 0 | 0 |  |
Fair Value, Inputs, Level 3 [Member] | Forward Starting Swaps [Member] |  |  |  |
Derivatives, Fair Value [Line Items] |  |  |  |
Derivative Asset | 0 | $ 0 |  |
Other Liabilities, Forward Starting Swaps | $ 0 |  |  |

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- Definition Fair value of employee holdings other than common shares within the supplemental executive retirement plan at the balance sheet date. + References No definition available. + Details
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- Definition The greater of carrying value (book value) or fair market value of an entity's issued and outstanding stock which is not included within permanent equity in Stockholders Equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. + References No definition available. + Details
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