Consolidation and Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) ft² in Thousands, $ in Thousands	6 Months Ended
Jun. 30, 2017 USD ($) ft² Property States Communities shares	Jun. 30, 2016 shares
Real Estate Properties [Line Items]
General Partners' Capital Account, Units Outstanding \| shares	113,607,734	75,524,086
Limited Liability (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest	0.9642203707
Number of owned or owned interests of apartment communities \| Property	305
Number of states in which apartment units are located \| States	16
Percentage Of Ownership Interests	100.00%
Minimum [Member]
Real Estate Properties [Line Items]
Percentage Of Ownership Interests	93.00%
Maximum [Member]
Real Estate Properties [Line Items]
Percentage Of Ownership Interests	100.00%
Development Properties [Member]
Real Estate Properties [Line Items]
Number of owned or owned interests of apartment communities \| Communities	6
Number of units under development community \| Property	1,766
Development Properties [Member] \| Expected Costs [Member]
Real Estate Properties [Line Items]
Development and capital improvements in progress	$ 396,100
Development Properties [Member] \| Costs Incurred to Date [Member]
Real Estate Properties [Line Items]
Development and capital improvements in progress	$ 293,100
Retail
Real Estate Properties [Line Items]
Number of owned or owned interests of apartment communities \| Property	29
Square Footage of Real Estate Property \| ft²	600
Commercial Real Estate [Member]
Real Estate Properties [Line Items]
Square Footage of Real Estate Property \| ft²	269
Apartment Building [Member]
Real Estate Properties [Line Items]
Number of owned or owned interests of apartment communities \| Communities	304
Secured Debt [Member] \| $750 million unsecured revolving credit facility [Member] \| Fair Market Value Adjustment and Debt Issuance Cost [Member]
Real Estate Properties [Line Items]
Debt Instrument, Face Amount	$ (26,944)
Post Massachusetts Avenue [Member]
Real Estate Properties [Line Items]
Equity Method Investment, Ownership Percentage	35.00%
Real Estate Investments, Joint Ventures	$ 44,800
Post River North [Member]
Real Estate Properties [Line Items]
Number of apartments included in a community	358
Development and capital improvements in progress	$ 51,600
Percentage Of Ownership Interests	92.50%
Land	$ 14,500
Accrued expenses and other liabilities	$ 5,800

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Property Held for Development

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Percentage Of Ownership Interests

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Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities.

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-Publisher FASB
-Name Accounting Standards Codification
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Area of a real estate property.

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Amount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

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Face (par) amount of debt instrument at time of issuance.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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The number of general partner units outstanding.

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

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The number of real estate properties owned as of the balance sheet date.

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The number of states the entity operates in as of the balance sheet date.

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The number of units in a real estate property owned as of the balance sheet date.

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The book value of investments in real estate joint ventures including direct and indirect investments.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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