Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended				12 Months Ended				12 Months Ended						1 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended			12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013 store tenant	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013 Options	Dec. 31, 2012 Options	Dec. 31, 2011 Options	Dec. 31, 2013 Director	Dec. 31, 2012 Director	Dec. 31, 2011 Director	Jul. 31, 2012 West Park	Dec. 31, 2012 West Park	Dec. 31, 2012 Belvedere	Dec. 31, 2012 Belvedere	Dec. 31, 2013 Park Van Ness	Dec. 31, 2012 Park Van Ness	Dec. 31, 2013 Minimum	Dec. 31, 2013 Minimum Building	Dec. 31, 2013 Maximum Building	Dec. 31, 2013 Maximum Building Improvements	Dec. 31, 2013 Giant Food store	Dec. 31, 2013 Safeway store
Significant Accounting Policies [Line Items]
Name of property															West Park		Belvedere
Number of shopping centers					32
Number of tenants					2
Percentage of total revenue																					2.50%				4.80%	2.60%
Number of shopping centers																									10	8
Interest expense capitalized					$ 170,000	$ 42,000	$ 1,896,000
Estimated useful life																						35 years	50 years	20 years
Depreciation expense and amortization of leasehold improvements					43,204,000	34,565,000	30,555,000
Repairs and maintenance expense					10,300,000	9,900,000	10,900,000
Deferred leasing costs, net	26,102,000				26,052,000	26,102,000
Accumulated amortization deferred leasing cost	16,200,000				16,600,000	16,200,000
Amortization expense deferred leasing cost					5,900,000	5,500,000	4,700,000
Construction in progress	2,267,000				9,867,000	2,267,000													7,900,000	2,300,000
Allowance for doubtful accounts receivables	1,208,000				572,000	1,208,000	671,000	898,000
Accounts receivable, net representing rental income accrued	34,400,000				37,200,000	34,400,000
Allowance for doubtful accounts receivables representing rental income accrued	92,000				500,000	92,000
Deferred debt costs, net	7,713,000				9,675,000	7,713,000
Accumulated amortization deferred leasing cost	3,800,000				4,500,000	3,800,000
Proceeds from sale of property					0	5,818,000	0									2,000,000		4,000,000
Gain on sale of property	3,453,000	1,057,000	0	0	0	4,510,000	0									1,100,000		3,400,000
Tax basis of the company's real estate investments	1,100,000,000				1,100,000,000	1,100,000,000
Shares credited to deferred fee accounts												226,996
Shares issued to directors, shares					56,002	158,219	49,570					200	200	200
Shares issued to directors, value												$ 124,400	$ 110,000	$ 109,000
Percentage of ownership in Operating Partnership					74.60%
Antidilutive options (in shares)									112,500	117,500	427,500