Organization and Significant Accounting Policies Revenues and Tenant and Other Receivables (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Schedule of management, transaction, and other fees [Line Items]
Other property income	$ 2,305	$ 1,982
Management, transaction, and other fees	6,816	6,972
Tenant and other receivables	148,058		$ 169,337
Management, transaction, and other fee [Member]
Schedule of management, transaction, and other fees [Line Items]
Tenant and other receivables	10,100		$ 11,600
Property management services [Member]
Schedule of management, transaction, and other fees [Line Items]
Management, transaction, and other fees	3,879	3,764
Asset management services [Member]
Schedule of management, transaction, and other fees [Line Items]
Management, transaction, and other fees	1,838	1,777
Leasing services [Member]
Schedule of management, transaction, and other fees [Line Items]
Management, transaction, and other fees	710	758
Other transaction fees [Member]
Schedule of management, transaction, and other fees [Line Items]
Management, transaction, and other fees	$ 389	$ 673