Notes Payable - Summary of Notes Payable (Parenthetical) (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Unamortized debt discount	$ 79,000
Revolving Credit Facility
Debt Instrument [Line Items]
Unsecured revolving credit facility	200,000,000
Revolving Credit Facility | Unsecured Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Amount Outstanding	101,900,000
Variable Rate Debt | Term Loan
Debt Instrument [Line Items]
Number of extensions	1
Extension period	1 year
Number of properties acquired	6
RIF V - Jersey, LLC | Fixed Rate Debt
Debt Instrument [Line Items]
Unamortized debt premium	38,000	50,000
Amortization period	30 years
The Park | Fixed Rate Debt
Debt Instrument [Line Items]
Amortization period	20 years
Unamortized debt discount	117,000	118,000
RIF V - Glendale Commerce Center, LLC | Variable Rate Debt
Debt Instrument [Line Items]
Number of extensions	2
Extension period	1 year
Maximum
Debt Instrument [Line Items]
Line of Credit Facility, Amount Outstanding	100,000,000
Maximum | Revolving Credit Facility | Unsecured Credit Facility
Debt Instrument [Line Items]
Additional interest	0.30%
Minimum
Debt Instrument [Line Items]
Line of Credit Facility, Amount Outstanding	$ 100,000,000
Minimum | Revolving Credit Facility | Unsecured Credit Facility
Debt Instrument [Line Items]
Additional interest	0.20%