Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) Employee Segment Room Property	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of Properties Acquired, Asset Acquisition | Property	3
Acquisition cost capitalized	$ 200,000
Document Period End Date	Dec. 31, 2017
Number of employees | Employee	194
Number of office, retail, multifamily and mixed-use operating properties | Property	26
Properties held for development | Property	4
Allowance for doubtful accounts	$ (400,000)	$ (400,000)
Total bad debt expense	800,000	800,000	$ 400,000
Real estate depreciation expense	$ 70,200,000	62,500,000	54,200,000
Short term liquid investments, initial maturity	3 months
Cash balance at banks, federally insured amount	$ 250,000
Cash balance at banks, excess of FDIC insured limit	45,700,000	37,100,000
Restricted cash	9,344,000	9,950,000	11,623,000
Incremental stock compensation cost from modification	$ 2,200,000	0	0
Number of operating segments | Segment	4
Rooms in mixed-use segment all-suite hotel | Room	369
Future minimum lease payments due	$ 38,326,000
Money Market Funds
Summary Of Significant Accounting Policies [Line Items]
Cash balance at banks, excess of FDIC insured limit	$ 29,400,000	200,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Percentage of taxable income required to distribute to qualify as real estate investment trust (REIT)	90.00%
Building And Improvement | Minimum
Summary Of Significant Accounting Policies [Line Items]
Real Estate, estimated useful lives	30 years
Building And Improvement | Maximum
Summary Of Significant Accounting Policies [Line Items]
Real Estate, estimated useful lives	40 years
Furniture And Equipment | Minimum
Summary Of Significant Accounting Policies [Line Items]
Real Estate, estimated useful lives	3 years
Furniture And Equipment | Maximum
Summary Of Significant Accounting Policies [Line Items]
Real Estate, estimated useful lives	15 years
Deferred Rent Receivables
Summary Of Significant Accounting Policies [Line Items]
Allowance for doubtful accounts	$ (1,400,000)	(1,300,000)
Other Income
Summary Of Significant Accounting Policies [Line Items]
General excise tax recognized, gross	$ 3,700,000	$ 3,800,000	3,700,000
Rancho Carmel Plaza
Summary Of Significant Accounting Policies [Line Items]
Gain on sale of property			$ 7,100,000