Leases (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) building
Lessee, Lease, Description [Line Items]
Pricing period	30 years
Number of buildings subleased | building	7
Rental and other revenues related to operating lease payments	$ 1,588,400
Rental and other revenues related to operating lease payments, variable leases	$ 200,564
Minimum
Lessee, Lease, Description [Line Items]
Lease term extension period	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease term extension period	25 years