Prepaid Expenses and Other Current Assets and Other Assets (Schedule of Other Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Prepaid Expenses and Other Current Assets and Other Assets [Abstract]
Straight-line rent receivable	$ 333,434	$ 321,816
Interest rate swap asset	38,032	12,123
Loan receivables	5,382	5,931
Deferred lease costs, net	4,960	4,788
Deferred tax asset - long term	38,890	53,722
Long-term investments	51,941	57,575
Other	19,359	22,037
Total other assets	$ 491,998	$ 477,992