Organization and Summary of Significant Accounting Policies (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Interest costs capitalized	$ 828,000	$ 554,000
Amortization of above and below market leases	698,000	660,000
Acquired-in-place leases	3,146,000	$ 3,327,000
Revolving credit facility borrowing capacity	900,000,000
Mortgages
Debt Instrument [Line Items]
Debt costs	147,000		$ 147,000
Debt costs accumulated amortization	60,000		55,000
Notes Payable to Banks
Debt Instrument [Line Items]
Debt costs	22,682,000		22,682,000
Debt costs accumulated amortization	$ 6,865,000		$ 6,337,000