Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014 sqft tenant store	Mar. 31, 2013	Dec. 31, 2013
Significant Accounting Policies [Line Items]
Number of tenants	1
Number of shopping centers	32
Allowance for doubtful accounts receivables	$ 400,000		$ 600,000
Period expected for the sale of property to occur	1 year
Area of leased property	70,040
Liabilities of assets held-for-sale	100,000
Construction in progress	11,880,000		9,867,000
Deferred debt costs, net	9,345,000		9,675,000
Accumulated amortization deferred leasing cost	4,800,000		4,500,000
Deferred leasing costs, net	25,996,000		26,052,000
Accumulated amortization deferred leasing cost	17,900,000		16,600,000
Amortization expense deferred leasing cost	1,300,000	1,600,000
Severance payments	1,100,000
Interest expensed capitalized	103,000	0
Commercial development projects, availability for occupancy, maximum period after major construction activity	1 year
Depreciation and amortization expense	8,900,000	14,800,000
Increase in depreciation expense	(5,900,000)
Repairs and maintenance expense	3,900,000	2,300,000
Property operating expenses	7,585,000	5,949,000
Shares credited to directors' deferred fee accounts	224,548
Percentage of ownership in Operating Partnership	74.40%
Options
Significant Accounting Policies [Line Items]
Antidilutive securities (in shares)	112,500	117,500
Held-for-sale
Significant Accounting Policies [Line Items]
Number of real estate properties	1
Snow removal costs
Significant Accounting Policies [Line Items]
Property operating expenses	1,700,000
Van Ness Square
Significant Accounting Policies [Line Items]
Construction in progress	9,700,000		7,900,000
Additional depreciation expense as a result of reduction in estimated useful life	6,000,000
Estimated remaining useful life	4 months
Other Assets | Assets Held-for-sale
Significant Accounting Policies [Line Items]
Assets held-for-sale	500,000
Accumulated depreciation	1,000,000
Minimum
Significant Accounting Policies [Line Items]
Accounts receivable, net representing rental income accrued	37,500,000		37,200,000
Allowance for doubtful accounts receivables representing rental income accrued	$ 500,000		$ 500,000
Minimum | Building
Significant Accounting Policies [Line Items]
Estimated useful life	35 years
Maximum | Building
Significant Accounting Policies [Line Items]
Estimated useful life	50 years
Maximum | Building Improvements
Significant Accounting Policies [Line Items]
Estimated useful life	20 years
Giant Food
Significant Accounting Policies [Line Items]
Number of shopping centers	10
Percentage of total revenue	4.90%
Safeway
Significant Accounting Policies [Line Items]
Number of shopping centers	8
Percentage of total revenue	2.70%
Revenues
Significant Accounting Policies [Line Items]
Number of tenants	2
Percentage of total revenue	2.50%