Property Acquisitions - Acquired Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Above- Market and Below- Market Leases [Member] | Operating Income [Member]
Business Acquisition [Line Items]
Amortization from acquired leases	$ 1,239,000	$ 986,000	$ 1,113,000
Above- Market and Below- Market Leases [Member] | Operating Expense [Member]
Business Acquisition [Line Items]
Amortization from acquired leases	333,000	353,000	529,000
Above- Market and Below- Market Leases [Member] | Prepaid Expenses And Other Assets [Member]
Business Acquisition [Line Items]
Finite lived intangible asset	3,300,000	3,784,000
Accumulated Amortization	3,220,000	2,727,000
Above- Market and Below- Market Leases [Member] | Accounts Payable and Accrued Liabilities [Member]
Business Acquisition [Line Items]
Accumulated Amortization	10,036,000	8,940,000
Finite lived intangible liabilities	7,531,000	8,685,000
In-Place Leases [Member]
Business Acquisition [Line Items]
Finite lived intangible asset	5,328,000	5,169,000
Accumulated Amortization	2,773,000	2,290,000
Depreciation and amortization expense	$ 518,000	$ 408,000	$ 241,000