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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 | Sep. 30, 2017 | Dec. 31, 2016
--- | --- | ---
Derivatives, Fair Value [Line Items] |  |
Fair Value Of SERP Investments | $ 136,774 | $ 124,420
Assets, Fair Value Disclosure | 141,139 | 126,277
Other Liabilities, Fair Value Disclosure | 136,774 | 124,420
Liabilities, Fair Value Disclosure | 136,774 | 124,420
Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners | 380,541 | 442,092
Fair Value Hedges [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Derivative Asset | 444 | 1,857
Forward Starting Swaps [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Derivative Asset | 3,921 |
Fair Value, Inputs, Level 1 [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Fair Value Of SERP Investments | 136,774 | 124,420
Assets, Fair Value Disclosure | 136,774 | 124,420
Other Liabilities, Fair Value Disclosure | 136,774 | 124,420
Liabilities, Fair Value Disclosure | 136,774 | 124,420
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 Asset | 0 | 0
Fair Value, Inputs, Level 1 [Member] | Forward Starting Swaps [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Derivative Asset | 0 |
Fair Value, Inputs, Level 2 [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Fair Value Of SERP Investments | 0 | 0
Assets, Fair Value Disclosure | 4,365 | 1,857
Other Liabilities, Fair Value Disclosure | 0 | 0
Liabilities, Fair Value Disclosure | 0 | 0
Redeemable Noncontrolling Interests – Operating Partnership/Redeemable Limited Partners | 380,541 | 442,092
Fair Value, Inputs, Level 2 [Member] | Fair Value Hedges [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Derivative Asset | 444 | 1,857
Fair Value, Inputs, Level 2 [Member] | Forward Starting Swaps [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Derivative Asset | 3,921 |
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 Asset | 0 | $ 0
Fair Value, Inputs, Level 3 [Member] | Forward Starting Swaps [Member] |  |
Derivatives, Fair Value [Line Items] |  |
Derivative Asset | $ 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 Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + 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://www.xbrl.org/2003/role/presentationRef -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 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13495-108611 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=82849420&loc=SL20226008-175313 + Details
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- Definition As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph (12)(c) -URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph (16)(c) -URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph 15 -URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph 14 -URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764 + Details
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