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Consolidation and Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) ft² in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2016 USD ($) ft² Property apartmentunits States Communities shares | Sep. 30, 2016 USD ($) ft² Property apartmentunits States Communities shares | Sep. 30, 2015 USD ($) shares
Real Estate Properties [Line Items] |  |  |
General Partners' Capital Account, Units Outstanding | shares | 75,542,583 | 75,542,583 | 75,379,381
Number of owned or owned interests of apartment communities | Property | 251 | 251 |
Number of apartments included in a community | apartmentunits | 79,170 | 79,170 |
Number of states in which apartment units are located | States | 15 | 15 |
Percentage Of Ownership Interests | 100.00% | 100.00% |
Minimum [Member] |  |  |
Real Estate Properties [Line Items] |  |  |
Percentage Of Ownership Interests | 95.00% | 95.00% |
Maximum [Member] |  |  |
Real Estate Properties [Line Items] |  |  |
Percentage Of Ownership Interests | 100.00% | 100.00% |
Development Properties [Member] |  |  |
Real Estate Properties [Line Items] |  |  |
Number of owned or owned interests of apartment communities | Communities | 3 | 3 |
Number of units under development community | Property | 550 | 550 |
Development Properties [Member] | Expected Costs [Member] |  |  |
Real Estate Properties [Line Items] |  |  |
Development and capital improvements in progress | $ 81,800,000 | $ 81,800,000 |
Development Properties [Member] | Costs Incurred to Date [Member] |  |  |
Real Estate Properties [Line Items] |  |  |
Development and capital improvements in progress | $ 48,600,000 | $ 48,600,000 |
Retail |  |  |
Real Estate Properties [Line Items] |  |  |
Number of owned or owned interests of apartment communities | Property | 6 | 6 |
Square Footage of Real Estate Property | ft² | 194 | 194 |
Interest Expense |  |  |
Real Estate Properties [Line Items] |  |  |
Prior Period Reclassification Adjustment | $ 900,000 |  | $ 2,700,000
Fair Market Value Adjustment and Debt Issuance Cost [Member] |  |  |
Real Estate Properties [Line Items] |  |  |
Prior Period Reclassification Adjustment |  |  | $ 2,700,000
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 | $ (19,011,000) | $ (19,011,000) |
Common Stock [Member] |  |  |
Real Estate Properties [Line Items] |  |  |
Merger Related Expenses |  | 38,000,000 |
Preferred Stock [Member] |  |  |
Real Estate Properties [Line Items] |  |  |
Merger Related Expenses |  | 868,000 |
Conversion of Stock, Name [Domain] |  |  |
Real Estate Properties [Line Items] |  |  |
Merger Related Expenses |  | 0.71 |
Equity Issued in Business Combination [Member] |  |  |
Real Estate Properties [Line Items] |  |  |
Merger Related Expenses |  | $ 80,000 |

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