Mortgages Payable and Debt Maturities - Summary of Debt Obligation and Interest Rate Derivatives (Parenthetical) (Detail)	3 Months Ended
Mar. 31, 2018
Line of credit - variable rate LIBOR + 1.10% (2.97% at March 31, 2018) [Member]
Debt Instrument [Line Items]
Interest rate at end of period	2.97%
Basis spread over LIBOR	1.10%
Term note - variable rate LIBOR + 1.15% (2.84% at March 31, 2018) [Member]
Debt Instrument [Line Items]
Basis spread over LIBOR	1.15%
Interest rate	2.84%
Term Note - Fixed Rate 5.54% [Member]
Debt Instrument [Line Items]
Interest rate	5.54%
Term Note - Fixed Rate 4.533% [Member]
Debt Instrument [Line Items]
Interest rate	4.533%
Term Note - Fixed Rate 3.50% [Member]
Debt Instrument [Line Items]
Interest rate	3.50%
Term Note - Fixed Rate 3.875% [Member]
Debt Instrument [Line Items]
Interest rate	3.875%
Term Note - Fixed Rate 3.67% [Member]
Debt Instrument [Line Items]
Interest rate	3.67%
Mortgage Note - Fixed Rate 4.98% [Member]
Debt Instrument [Line Items]
Interest rate	4.98%
Mortgage Note - Fixed Rate 4.065% [Member]
Debt Instrument [Line Items]
Interest rate	4.065%
Mortgage Note - Fixed Rate 5.26% [Member]
Debt Instrument [Line Items]
Interest rate	5.26%
Mortgage Note - Fixed Rate 5.99% [Member]
Debt Instrument [Line Items]
Interest rate	5.99%

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

No definition available.

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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

+ Details

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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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- Definition

The effective interest rate at the end of the reporting period.

+ 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 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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