Summary of Information Concerning Indebtedness that Encumbered our Properties (Parenthetical) (Detail)	6 Months Ended	12 Months Ended
Jun. 30, 2015	Dec. 31, 2014
Centrepoint Apartments
Mortgage Loans on Real Estate [Line Items]
Interest payment period	Monthly
Principal date	Feb. 01, 2015	Feb. 01, 2015
Amortization schedule	30 years	30 years
Berkshire Square Apartments
Mortgage Loans on Real Estate [Line Items]
Interest payment period	Monthly
Principal date	Feb. 01, 2016	Feb. 01, 2016
Amortization schedule	30 years	30 years
OKC Portfolio
Mortgage Loans on Real Estate [Line Items]
Amortization schedule	30 years	30 years
Contractual interest rate	5.60%	5.60%
King's Landing
Mortgage Loans on Real Estate [Line Items]
Interest payment period	Monthly
Principal date	Jun. 01, 2017	Jun. 01, 2017
Amortization schedule	30 years	30 years
Belle Creek Apartments \| Floating Rate
Mortgage Loans on Real Estate [Line Items]
Debt instrument interest rate	2.25%	2.25%
Belle Creek Apartments \| 30-Day LIBOR
Mortgage Loans on Real Estate [Line Items]
Debt instrument interest rate	0.19%	0.17%
Tresa At Arrowhead \| Floating Rate
Mortgage Loans on Real Estate [Line Items]
Debt instrument interest rate	2.25%	2.25%
Tresa At Arrowhead \| 30-Day LIBOR
Mortgage Loans on Real Estate [Line Items]
Debt instrument interest rate	0.19%	0.17%
Secured Credit Facility \| Floating Rate
Mortgage Loans on Real Estate [Line Items]
Debt instrument interest rate	2.50%	2.50%
Secured Credit Facility \| 30-Day LIBOR
Mortgage Loans on Real Estate [Line Items]
Debt instrument interest rate	0.19%	0.17%

Date the debt agreement requires a change in payment type from interest only to principal and interest.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 50

-Paragraph 3

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

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.

+ References

No definition available.

+ Details

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