Organization and Summary of Significant Accounting Policies (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Interest costs capitalized	$ 596,000	$ 581,000	$ 2,500,000	$ 1,694,000
Amortization of above and below market leases	219,000	1,355,000	2,334,000	2,696,000
Revolving credit facility borrowing capacity	900,000,000		900,000,000
Mortgages
Debt Instrument [Line Items]
Debt costs	147,000		147,000		$ 147,000
Debt costs accumulated amortization	69,000		69,000		55,000
Notes Payable to Banks
Debt Instrument [Line Items]
Debt costs	29,707,000		29,707,000		22,682,000
Debt costs accumulated amortization	7,952,000		7,952,000		$ 6,337,000
In-place leases, net
Debt Instrument [Line Items]
Acquired-in-place leases	$ 1,789,000	$ 7,875,000	$ 7,305,000	$ 14,483,000