Leases - Narrative (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
Lessee, Lease, Description [Line Items]
Straight line rent adjustment			$ 49,241	$ 146,508
Rental and other revenues related to operating lease payments	$ 357,984	$ 275,046	1,015,550	1,061,311
Rental and other revenues related to operating lease payments, variable leases			$ 134,632	$ 153,217
Belmont Village
Lessee, Lease, Description [Line Items]
Straight line rent adjustment					$ 91,025
Minimum
Lessee, Lease, Description [Line Items]
Lease term extension period			1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease term extension period			25 years