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Summary of Significant Accounting Policies - Additional Information (Details) | 12 Months Ended
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Dec. 31, 2017 USD ($) Property ApartmentUnit $ / shares | Dec. 31, 2016 USD ($) $ / shares | Dec. 31, 2015 USD ($) $ / shares
Properties | Property | 305 |  |
Value of furniture and fixtures minimum range | $ 10,000 |  |
Value of furniture and fixtures maximum range | $ 25,000 |  |
Lease intangibles, average term | 6 months |  |
Capitalized costs development and renovation | $ 14,700,000 | $ 18,700,000 | $ 22,300,000
Common Stock, Par or Stated Value Per Share | $ / shares | $ 0.01 | $ 0.01 | $ 0.01
Land and depreciable property net | $ 14,800,000,000 | $ 15,800,000,000 |
Noncontrolling interests partially owned properties | $ 4,708,000 | $ 10,609,000 |
Apartment units | ApartmentUnit | 78,611 |  |
Minimum [Member] | Retail Commercial Leases [Member] |  |  |
Retail/commercial leases term | 5 years |  |
Maximum [Member] | Retail Commercial Leases [Member] |  |  |
Retail/commercial leases term | 10 years |  |
Furniture and Fixtures [Member] | Minimum [Member] |  |  |
Property, plant and equipment, estimated useful lives | 5 years |  |
Furniture and Fixtures [Member] | Maximum [Member] |  |  |
Property, plant and equipment, estimated useful lives | 10 years |  |
Building [Member] |  |  |
Property, plant and equipment, estimated useful lives | 30 years |  |
Building Improvements [Member] |  |  |
Property, plant and equipment, estimated useful lives | 8 years |  |
Replacements [Member] | Minimum [Member] |  |  |
Property, plant and equipment, estimated useful lives | 5 years |  |
Replacements [Member] | Maximum [Member] |  |  |
Property, plant and equipment, estimated useful lives | 10 years |  |
Renovations and Improvements Minimum [Member] | Minimum [Member] |  |  |
Property, plant and equipment, estimated useful lives | 5 years |  |
Renovations and Improvements Minimum [Member] | Maximum [Member] |  |  |
Property, plant and equipment, estimated useful lives | 15 years |  |
Partially Owned Properties – Unconsolidated |  |  |
Properties | Property | 2 |  |
Noncontrolling interests partially owned properties | $ 137,152,000 |  |
Apartment units | ApartmentUnit | 945 |  |
Partially Owned Properties – Consolidated |  |  |
Properties | Property | 17 |  |
Noncontrolling interests partially owned properties | $ 4,700,000 |  |
Apartment units | ApartmentUnit | 3,215 |  |
Limited Life Partnership Properties [Member] |  |  |
Properties | Property | 4 |  |
Noncontrolling interests partially owned properties | $ 8,800,000 |  |
Noncontrolling interests settlement value | $ 65,400,000 |  |

X
- Definition Represents payroll and associated costs of employees directly responsible for and who spend their time on the supervision of development activities as well as major capital and/or renovation projects that are capitalized on the balance sheet + References No definition available. + Details
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- Definition Represents the value of Noncontrolling Interest distributions had the Company's partnership agreements been liquidated through the sale of their assets upon reaching the date specified in each respective partnership agreement. The Company, as controlling partner, has an obligation to cause the property owning partnerships to distribute the proceeds of liquidation to the Noncontrolling Interests in these Partially Owned Properties. + References No definition available. + Details
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- Definition Value of the minimum amount applied on a per apartment unit basis to estimate the fair value of furniture and fixtures inside the unit for newly acquired properties based on economic age. + References No definition available. + Details
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- Definition Term of the lessor's leasing arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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