Property, net - Components of Property (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Land	$ 1,506,678		$ 1,567,152
Buildings and improvements	6,288,308		6,385,035
Tenant improvements	678,110		620,352
Equipment and furnishings	206,398	$ 206,398	187,998
Construction in progress	199,326	$ 199,326	366,996
Total	8,878,820		9,127,533
Less accumulated depreciation	(2,093,044)		(2,018,303)
Property, net	$ 6,785,776		$ 7,109,230

The current amount of expenditures for a real estate project that has not yet been completed.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
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- Definition

Amount before accumulated depreciation of fixtures and equipment. Includes, but is not limited to, machinery, equipment, and engines.

+ References

No definition available.

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- Definition

Aggregate of the carrying amounts as of the balance sheet date of investments in building and building improvements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.13)
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- References

No definition available.

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- Definition

The cumulative amount of depreciation for real estate property held for investment purposes.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

+ References

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- Definition

Carrying amount as of the balance sheet date of improvements having a life longer than one year that were made for the benefit of one or more tenants.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
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