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	Mar. 31, 2019	Dec. 31, 2018
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable	$ 80,000	$ 80,000
Note receivable	19,593	19,468
Mortgage notes payable, net	2,959,908	2,964,572
Unsecured senior notes, net	7,547,043	7,544,697
Unsecured line of credit	0	0
Unsecured term loan, net	498,607	498,488
Carrying Amount [Member]
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable	80,000	80,000
Note receivable	19,593	19,468
Note and Related Party Receivables	99,593	99,468
Mortgage notes payable, net	2,959,908	2,964,572
Unsecured senior notes, net	7,547,043	7,544,697
Unsecured line of credit	0	0
Unsecured term loan, net	498,607	498,488
Total	11,005,558	11,007,757
Estimated Fair Value [Member]
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable	80,060	80,000
Note receivable	17,723	19,468
Note and Related Party Receivables	97,783	99,468
Mortgage notes payable, net	2,948,057	2,903,925
Unsecured senior notes, net	7,584,456	7,469,338
Unsecured line of credit	0	0
Unsecured term loan, net	500,728	500,783
Total	$ 11,033,241	$ 10,874,046