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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 | Jun. 30, 2018 | Dec. 31, 2017
--- | --- | ---
Derivatives, Fair Value [Line Items] |  |
Fair Value Of SERP Investments | $ 140,432 | $ 140,159
Assets, Fair Value Disclosure | 157,163 | 145,302
Other Liabilities, Fair Value Disclosure | 140,432 | 140,159
Liabilities, Fair Value Disclosure | 145,411 | 141,756
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners | 366,483 | 366,955
Fair Value Hedges [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Derivative liability, fair value | 3,748 | 1,597
Forward Starting Swaps [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Derivative Asset | 16,731 | 5,143
Other Liabilities, Forward Starting Swaps | 1,231 |
Fair Value, Inputs, Level 1 [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Fair Value Of SERP Investments | 140,432 | 140,159
Assets, Fair Value Disclosure | 140,432 | 140,159
Other Liabilities, Fair Value Disclosure | 140,432 | 140,159
Liabilities, Fair Value Disclosure | 140,432 | 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 | 16,731 | 5,143
Other Liabilities, Fair Value Disclosure | 0 | 0
Liabilities, Fair Value Disclosure | 4,979 | 1,597
Redeemable Noncontrolling Interests - Operating Partnership/Redeemable Limited Partners | 366,483 | 366,955
Fair Value, Inputs, Level 2 [Member] | Fair Value Hedges [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Derivative liability, fair value | 3,748 | 1,597
Fair Value, Inputs, Level 2 [Member] | Forward Starting Swaps [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Derivative Asset | 16,731 | 5,143
Other Liabilities, Forward Starting Swaps | 1,231 |
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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- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
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