Basis Of Presentation And Summary Of Significant Accounting Policies (Carrying Value Of note receivable, Indebtedness And Corresponding Estimate Of Fair Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable	$ 80,000	$ 0
Mortgage notes payable, net	2,967,548	2,979,281
Unsecured senior notes, net	7,253,786	7,247,330
Unsecured line of credit	170,000	45,000
Unsecured term loan, net	498,368	0
Carrying Amount [Member]
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable	80,000	0
Mortgage notes payable, net	2,967,548	2,979,281
Unsecured senior notes, net	7,253,786	7,247,330
Unsecured line of credit	170,000	45,000
Unsecured term loan, net	498,368	0
Total	10,889,702	10,271,611
Estimated Fair Value [Member]
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable	80,000	0
Mortgage notes payable, net	2,898,871	3,042,920
Unsecured senior notes, net	7,174,434	7,461,615
Unsecured line of credit	170,287	45,000
Unsecured term loan, net	502,110	0
Total	$ 10,745,702	$ 10,549,535