Leases (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Operating Leased Assets [Line Items]
Fixed and in-substance fixed lease income		$ 201,183	$ 200,020	$ 594,471	$ 607,429
Variable lease income		62,810	60,535	195,538	186,952
Uncollectible straight-line rent		3,655	(7,678)	(172)	(27,867)
Uncollectible amounts billable in lease income		9,198	(26,147)	18,093	(65,991)
Total lease income		283,303	234,541	826,390	731,630
Accounts and Notes Receivable, Net		139,287		139,287		$ 143,633
Straight-line rent receivables				95,588		86,615
Tenant Receivables [Member]
Operating Leased Assets [Line Items]
Accounts and Notes Receivable, Net		24,210		24,210		39,658
Other Receivable [Member]
Operating Leased Assets [Line Items]
Accounts and Notes Receivable, Net	[1]	19,489		19,489		$ 17,360
Lessor [Member]
Operating Leased Assets [Line Items]
Above/below market rent and tenant rent inducement amortization, net		$ 6,457	$ 7,811	$ 18,460	$ 31,107

[1] Other receivables include construction receivables, insurance receivables, and amounts due from real estate partnerships for Management, transaction and other fee income.